This file is indexed.

/usr/share/doc/ltsp/LTSPManual.html is in ltsp-docs 1.1-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Linux Terminal Server Project Administrator's Reference</title><meta name="generator" content="DocBook XSL Stylesheets V1.76.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="book" title="Linux Terminal Server Project Administrator's Reference"><div class="titlepage"><div><div><h1 class="title"><a name="idp44304"></a>Linux Terminal Server Project Administrator's Reference</h1></div><div><h2 class="subtitle">
        A Guide to LTSP Networks
    </h2></div><div><div class="authorgroup"><div class="author"><h3 class="author"><span class="firstname">Scott</span> <span class="surname">Balneaves</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Jordan</span> <span class="surname">Erickson</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Francis</span> <span class="surname">Giraldeau</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Richard</span> <span class="surname">Johnson</span></h3></div><div class="author"><h3 class="author"><span class="firstname">David</span> <span class="surname">Johnston</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Chuck</span> <span class="surname">Liebow</span></h3></div><div class="author"><h3 class="author"><span class="firstname">James</span> <span class="surname">McQuillan</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Jonathan</span> <span class="surname">Mueller</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Gideon</span> <span class="surname">Romm</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Joel</span> <span class="surname">Sass</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Robin</span> <span class="surname">Shepheard</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Susan</span> <span class="surname">Stewart</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Brian</span> <span class="surname">Tilma</span></h3></div><div class="author"><h3 class="author"><span class="firstname">David</span> <span class="surname">Van Assche</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Carol</span> <span class="surname">Wiebe</span></h3></div><div class="author"><h3 class="author"><span class="firstname">Vagrant</span> <span class="surname">Cascadian</span></h3></div></div></div><div><p class="copyright">Copyright © 2008, 2012 Scott Balneaves and other authors</p></div><div><div class="legalnotice" title="Legal Notice"><a name="idp48008"></a><p>
                Permission to use, copy, modify and distribute
                the software and its accompanying documentation for any
                purpose and without fee is hereby granted in perpetuity under
                the terms of the GNU GPL2,
                provided that a copy of the GNU GPL2 appears
                with it.
            </p></div></div><div><div class="legalnotice" title="Legal Notice"><a name="idp48752"></a><p>
                The copyright holder makes no representation about the
                suitability of this software for any purpose. It is provided
                <span class="quote">&#8220;<span class="quote">as is</span>&#8221;</span> without expressed or implied
                warranty.  If you modify the software in any way, identify your
                software as a variant of LTSP.
            </p></div></div><div><p class="pubdate">June 2012</p></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="chapter"><a href="#intro">1. Linux Terminal Server Project - LTSP</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2135064">Introduction to LTSP and Thin Client Computing</a></span></dt><dt><span class="sect1"><a href="#idp1714688">LTSP Security</a></span></dt><dt><span class="sect1"><a href="#idp2210064">LTSP Manageability</a></span></dt><dt><span class="sect1"><a href="#idp2058872">It's Green!</a></span></dt><dt><span class="sect1"><a href="#idp2040872">Cost Effective </a></span></dt><dt><span class="sect1"><a href="#idp51600">Well Supported</a></span></dt><dt><span class="sect1"><a href="#idp27768">Built for Education, Government and business</a></span></dt></dl></dd><dt><span class="chapter"><a href="#basic-concepts">2. Basic Concepts: Networks and Networking </a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp31400">Hardware </a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp33008">Wired</a></span></dt><dt><span class="sect2"><a href="#idp37040">Wireless</a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp40560">Software</a></span></dt><dt><span class="sect1"><a href="#idp130464">How LTSP Works</a></span></dt></dl></dd><dt><span class="chapter"><a href="#tc-hardware">3. LTSP Thin Client hardware requirements</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2866968">Hardware reuse and sizing</a></span></dt><dt><span class="sect1"><a href="#idp2869992">Clients</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2870312">Older hardware</a></span></dt><dt><span class="sect2"><a href="#idp2873288">CPU</a></span></dt><dt><span class="sect2"><a href="#idp2874936">Network</a></span></dt><dt><span class="sect2"><a href="#idp2879704">Thin client memory</a></span></dt><dt><span class="sect2"><a href="#idp2880608">Video Card</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#server-hardware">4. LTSP Server requirements</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2882432">Recommended specs</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2883712">Memory</a></span></dt><dt><span class="sect2"><a href="#idp2886592">Processors</a></span></dt><dt><span class="sect2"><a href="#idp2888904">Disks</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#network">5. Network</a></span></dt><dt><span class="chapter"><a href="#chroot">6. The LTSP chroot environment</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2898912">The boot process of a thin client</a></span></dt></dl></dd><dt><span class="chapter"><a href="#network-boot">7. Network booting the thin client</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2937488">Boot ROM</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2938304">Etherboot</a></span></dt><dt><span class="sect2"><a href="#idp2940632">PXE</a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp2942904">Local media</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2943776">Floppy disk</a></span></dt><dt><span class="sect2"><a href="#idp2944832">Hard disk</a></span></dt><dt><span class="sect2"><a href="#idp2945696">CD-ROM</a></span></dt><dt><span class="sect2"><a href="#idp2946424">USB Memory device</a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp2947240">Installation</a></span></dt></dl></dd><dt><span class="chapter"><a href="#customizing-ltsconf">8. Customizing thin client behaviour</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2951280">Location of the lts.conf file</a></span></dt><dt><span class="sect1"><a href="#idp2953632">Sample lts.conf file</a></span></dt></dl></dd><dt><span class="chapter"><a href="#lts-conf">9. Format of the lts.conf file</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2958520">Section headings </a></span></dt><dt><span class="sect1"><a href="#idp2960384">Variable Assignments</a></span></dt><dt><span class="sect1"><a href="#idp2962184">The LIKE keyword</a></span></dt></dl></dd><dt><span class="chapter"><a href="#general-parms">10. General thin client parameters</a></span></dt><dt><span class="chapter"><a href="#localdev-parms">11. Local Device thin client parameters</a></span></dt><dt><span class="chapter"><a href="#screen-scripts">12. Screen Scripts</a></span></dt><dt><span class="chapter"><a href="#rdesktop">13. The "rdesktop" screen script</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2975632">Single Line</a></span></dt><dt><span class="sect1"><a href="#idp2978088">Multiple Line</a></span></dt><dt><span class="sect1"><a href="#idp2980056">RDP + Local Devices</a></span></dt><dt><span class="sect1"><a href="#idp2984840">RDP + Local Sound</a></span></dt></dl></dd><dt><span class="chapter"><a href="#modules-scripts">14. Modules and startup scripts</a></span></dt><dt><span class="chapter"><a href="#sound">15. Sound in LTSP</a></span></dt><dt><span class="chapter"><a href="#xwin-parms">16. X-Windows parameters</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2994168">X.org Configuration</a></span></dt></dl></dd><dt><span class="chapter"><a href="#xrandr">17. XRANDR setting for managing displays</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp2996304">New Xorg structure within LTSP</a></span></dt><dt><span class="sect1"><a href="#idm9104">Script structure</a></span></dt><dt><span class="sect1"><a href="#idm3504">XRandR parameters</a></span></dt></dl></dd><dt><span class="chapter"><a href="#printer">18. Printer configuration parameters</a></span></dt><dt><span class="chapter"><a href="#keyboard">19. Keyboard parameters</a></span></dt><dt><span class="chapter"><a href="#touchscreen">20. Touchscreen configuration</a></span></dt><dt><span class="chapter"><a href="#localapps">21. Local Applications</a></span></dt><dt><span class="chapter"><a href="#ldm">22. The LDM display manager</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp3023368">Introduction</a></span></dt><dt><span class="sect1"><a href="#idp3028048">Theory of operation</a></span></dt><dt><span class="sect1"><a href="#idp3036008">Encrypted versus unencrypted sessions</a></span></dt><dt><span class="sect1"><a href="#idp3038048">Auto login features</a></span></dt><dt><span class="sect1"><a href="#idp3039912">Load balancing features</a></span></dt><dt><span class="sect1"><a href="#idp3041328">RC script capabilities</a></span></dt><dt><span class="sect1"><a href="#idp3054464">LDM lts.conf parameters</a></span></dt><dt><span class="sect1"><a href="#idp3055304">Multiple server setup</a></span></dt></dl></dd><dt><span class="chapter"><a href="#infrastructure">23. Infrastructure setup</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp3057032">Network topology</a></span></dt><dt><span class="sect1"><a href="#idp3058656">Common authentication</a></span></dt><dt><span class="sect1"><a href="#idp3062080">Shared home directories</a></span></dt><dt><span class="sect1"><a href="#idp3063160">Shared printers</a></span></dt><dt><span class="sect1"><a href="#idp3064320">Managing the SSH known hosts file</a></span></dt><dt><span class="sect1"><a href="#idp3067416">Setting Network Forwarding or Masquerading</a></span></dt></dl></dd><dt><span class="chapter"><a href="#session-dispatching">24. Session dispatching</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp3075136">Define the server list</a></span></dt><dt><span class="sect1"><a href="#idp3079064">Dispatching method</a></span></dt><dt><span class="sect1"><a href="#idp3082864">Network Swap</a></span></dt><dt><span class="sect1"><a href="#idp3088536">Managing DHCP</a></span></dt></dl></dd><dt><span class="chapter"><a href="#static-entries-dhcp">25. Adding static entries to the dhcpd.conf</a></span></dt><dt><span class="chapter"><a href="#dhcp-loadbalance">26. DHCP failover load balancing</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp3100080"></a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp3100640">Lockdown with Sabayon (user profile manager) and
                    Pessulus (lockdown editor)
                </a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp3105288">Replication of desktop profiles</a></span></dt></dl></dd><dt><span class="chapter"><a href="#managing-clients">27. Managing the thin client</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp3107856">Lockdown Editor</a></span></dt></dl></dd><dt><span class="chapter"><a href="#updating-chroot">28. Updating your LTSP chroot</a></span></dt><dt><span class="chapter"><a href="#changing-server-ip">29. Changing the IP of your LTSP server</a></span></dt><dt><span class="chapter"><a href="#appendix">30. Appendix I</a></span></dt><dd><dl><dt><span class="sect1"><a href="#idp3123312">Using NFS instead of NBD</a></span></dt><dt><span class="sect1"><a href="#idp3131920">Enabling dual monitors</a></span></dt></dl></dd></dl></div><div class="chapter" title="Chapter 1. Linux Terminal Server Project - LTSP"><div class="titlepage"><div><div><h2 class="title"><a name="intro"></a>Chapter 1. Linux Terminal Server Project - LTSP</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2135064">Introduction to LTSP and Thin Client Computing</a></span></dt><dt><span class="sect1"><a href="#idp1714688">LTSP Security</a></span></dt><dt><span class="sect1"><a href="#idp2210064">LTSP Manageability</a></span></dt><dt><span class="sect1"><a href="#idp2058872">It's Green!</a></span></dt><dt><span class="sect1"><a href="#idp2040872">Cost Effective </a></span></dt><dt><span class="sect1"><a href="#idp51600">Well Supported</a></span></dt><dt><span class="sect1"><a href="#idp27768">Built for Education, Government and business</a></span></dt></dl></div><div class="sect1" title="Introduction to LTSP and Thin Client Computing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2135064"></a>Introduction to LTSP and Thin Client Computing</h2></div></div></div><p>
                One of the key technologies included in modern GNU/Linux
                operating systems is the Linux Terminal Server Project (LTSP)
                which allows you to boot thin clients from an LTSP server. For
                educational environments, LTSP lowers hardware costs by
                enabling the use of older or less powerful machines as thin
                clients, as well as reduced administration overhead by having
                only to install and maintain the software on the server. When
                a workstation fails, it can simply be replaced without data
                loss or re-installation of the operating system.
            </p><p>
                Thin client computing has been around for a long time in the
                UNIX world. Although the implementation has evolved quite a
                bit, the concept has remained the same:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        The thin client only takes care of the basic
                        functions like display, keyboard, mouse and sound.
                    </p></li><li class="listitem"><p>
                        The server does the heavy weightlifting. All the
                        applications run on the server, and they simply
                        display on the thin client.
                    </p></li></ol></div><p>
                Because the thin clients have a limited number of tasks to
                manage, the hardware for the thin client can be small and
                cheap. The thin clients themselves are basically maintenance
                free. They last longer because they have no storage with
                moving parts like hard disks. If they break no data is lost
                since nothing is stored on the client itself. Simply swap the
                client with another one and go back to work. If your thin
                client is stolen or put in the trash, no data ends up in the
                hands of unauthorized people.
            </p><p>
                The terminal server runs all applications and contains all
                the data. All the regular maintenance (software updates,
                administration) takes place on the terminal server. The number
                of thin clients that a terminal server can support is
                proportional to the power of the server. Because GNU/Linux
                makes efficient use of resources, you can support a surprising
                number of thin clients from a machine which might only be
                considered a powerful single user system running other
                operating systems. Please see for more details.
            </p><p>
                In a thin client computing environment, the stability of the
                server is important. It's important to make sure that your
                server has good power fallback facilities, like installing a
                UPS, and depending on how much availability is required,
                redundant power supplies may be called for. As well, users who
                have the resources may decide to invest in multiple disks for
                RAID support, and other options which may be needed in a High
                Availability environment. However, you certainly don't need
                them in all environments, and GNU/Linux's high quality means
                that in all but the most demanding environments, this won't be
                needed.
            </p></div><div class="sect1" title="LTSP Security"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp1714688"></a>LTSP Security</h2></div></div></div><p>
                Security has become a key challenge for administrators and
                LTSP both recognizes and handles this quite well. Often
                schools lack the specialized IT staff or time to lock and
                clean up computers.
            </p><p>
                Operating systems with LTSP included, being Linux-based
                operating systems, enjoy the security advantages of its
                Unix-like and open source heritages. This translates into
                higher quality code and no spyware and viruses, like they
                plague other operating systems.
            </p><p>
                In addition, it has a strict, proactive security policy
                which means that many common problems, such as open ports or
                misconfigured software, never make it into the released
                product. Finally, LTSP based systems are true multi-user
                operating systems, making it easy to allow users to complete
                their tasks without having a level of access that could
                compromise the system.
            </p></div><div class="sect1" title="LTSP Manageability"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2210064"></a>LTSP Manageability</h2></div></div></div><p>
                With administrators and especially school IT departments
                deploying and administering an increasing number of computers,
                it is difficult to find time to manage individual machines.
                LTSP thin client technology, makes deployment and management
                simple and easy. A single server is all that is needed to set
                up, manage and administrate an entire network It is recognized
                that not every school's setup is the same, so LTSP (and the
                underlying operating system) has been made to easily customize
                your unique needs.
            </p></div><div class="sect1" title="It's Green!"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2058872"></a>It's Green!</h2></div></div></div><p>
                With the ongoing debate about climate change, questions are
                finally being asked and answered in the fields of IT,
                education and thin client technology in general. A recent
                study compared the energy and resource consumption of a
                regular PC and Thin Client setups. You can find that study
                here: <a class="ulink" href="http://it.umsicht.fraunhofer.de/TCecology/index_en.html" target="_top">
                http://it.umsicht.fraunhofer.de/TCecology/index_en.html
                </a>
            </p><p>
                They found that thin clients use half the energy of
                traditional workstations, which not only helps on the cost
                savings (calculate that a 40 terminal thin client lab will
                save approximately $500-$800 per year), but is ecologically
                effective in avoiding electronic waste and high carbon
                emissions. Thin client production, assembly and logistics
                costs far less and requires less energy than traditional PC
                manufacturing. The recycling of old machinery also helps the
                environment, making LTSP a green solution to the environmental
                and power saving issues many IT managers face today.
            </p></div><div class="sect1" title="Cost Effective"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2040872"></a>Cost Effective </h2></div></div></div><p>
                With ever-increasing demands on school budgets, expensive
                technology is often last on the list. LTSP can help you offer
                what your students increasingly require from computer
                technology, without breaking the bank. GNU/Linux is and always
                will be free to acquire, use and modify, including the
                underlying LTSP structure that holds it all together.
            </p><p>
                Need to set up another machine? Or another 100? Just install
                them! With GNU/Linux you'll have no more expensive OS upgrades
                and licenses, and having specialized programs on only some
                computers will become a thing of the past. When you build your
                network on Open Source software, you are freed to seek support
                for your computers from whomever you wish.
            </p><p>
                GNU/Linux with LTSP can also help you save hardware costs, by
                allowing you to redeploy older machines as thin clients using
                LTSP technology. Whether you choose to set up many smaller
                labs with various LTSP servers or one giant setup with a load
                balanced LTSP setup (various servers working together to
                manage the users and applications logging on) the cost savings
                are always enormous.
            </p></div><div class="sect1" title="Well Supported"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp51600"></a>Well Supported</h2></div></div></div><p>
                LTSP support is available from the LTSP community. Many
                of the authors of the software included in LTSP, including the
                respective developers of the various LTSP GNU/Linux
                distribution implementations themselves, can be contacted
                directly via mailing lists and IRC channels.
            </p><p>
                There are many forms of support available, including mailing
                lists, Wiki websites, IRC channels, and bug trackers. There
                are also special support groups for using LTSP and GNU/Linux.
            </p><p>
                The official IRC support channel is found on freenode.org at
                #ltsp
            </p><p>
                The official LTSP mailing list is found here:</p><p>
                <a class="ulink" href="https://lists.sourceforge.net/lists/listinfo/ltsp-discuss" target="_top">
                    https://lists.sourceforge.net/lists/listinfo/ltsp-discuss
                </a>
            </p><p>
                In fact, some of the money that would have gone to
                purchasing software can instead be spent to hire local experts
                to help train you, and to help you support your network. LTSP
                can help you take more control over your network while also
                benefiting your local economy. With LTSP based systems, these
                choices are yours.
            </p></div><div class="sect1" title="Built for Education, Government and business"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp27768"></a>Built for Education, Government and business</h2></div></div></div><p>
                LTSP based distros come with translations for many languages
                and localization features that allow people from all over the
                world to enjoy their computing experience. Accessibility
                features strive to provide a pleasant, high-quality computing
                experience to disabled users.
            </p><p>
                The Free nature of GNU/Linux means that the applications a user
                is used to at their school or workplace is also available to
                them at home.  Users can install their favorite
                GNU/Linux distribution at home, and have all the same
                functionality they are used to.  In fact, many GNU/Linux
                distributions have Live CD's, which allow users to try, or even
                fully use the distribution at home, without even installing it
                on their home machine.
            </p><p>
                The LTSP server software allows administrators, IT managers
                and teachers to create a low cost computer lab so that users
                can have access to the opportunities that GNU/Linux and the
                Internet can provide.
            </p><p>
                Since setups can be adjusted to many situations, each thin
                client lab can be uniquely tailored to fit the business,
                agency or educational facility in question.
            </p></div></div><div class="chapter" title="Chapter 2. Basic Concepts: Networks and Networking"><div class="titlepage"><div><div><h2 class="title"><a name="basic-concepts"></a>Chapter 2. Basic Concepts: Networks and Networking </h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp31400">Hardware </a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp33008">Wired</a></span></dt><dt><span class="sect2"><a href="#idp37040">Wireless</a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp40560">Software</a></span></dt><dt><span class="sect1"><a href="#idp130464">How LTSP Works</a></span></dt></dl></div><p>
            There are two components of a network: hardware and software.
            This section will give an introduction to both.
        </p><div class="sect1" title="Hardware"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp31400"></a>Hardware </h2></div></div></div><p>
                Networking works by breaking files and other data into
                little packets of information. These packets are transferred
                over a network. The difference between various types of
                networks is how they transfer packets.
            </p><p>
                There are two types of networking hardware: wired and
                wireless.
            </p><p>
                An important fact to remember is that a network will be only
                as fast as the slowest part. Making sure that your network
                setup matches your intended use case is an important
                consideration in an LTSP network.
            </p><div class="sect2" title="Wired"><div class="titlepage"><div><div><h3 class="title"><a name="idp33008"></a>Wired</h3></div></div></div><p>
                    Wired networking transfers packets over a cable that
                    resembles a telephone cord, but with more wires. Wired
                    networks can transfer packets at one of three possible
                    speeds: 10 Mbit/sec, 100 Mbit/sec, or (Gigabit) 1000
                    Mbit/sec.
                </p><p>
                    A network is only useful if it can connect multiple
                    computers. There are some pieces of hardware that allow
                    multiple computers to be connected in a network. They look
                    alike, but they function differently and, likewise,
                    operate at different speeds.
                </p><p><span class="emphasis"><em>Hub</em></span></p><p>
                    A hub is the simplest way to connect multiple computers.
                    A hub has a lot of ports in the front and usually has
                    several small lights corresponding to each port. The hub
                    takes a message it receives on one port and re-sends it to
                    all the ports. As a result, only one port can talk at a
                    time.
                </p><p><span class="emphasis"><em>Switch</em></span></p><p>
                    A switch looks a lot like a hub; it has a lot of ports
                    in the front and usually has several small lights
                    corresponding to each port. However, a switch is unlike a
                    hub because it only makes a connection between the ports
                    it needs to. A switch can have multiple connections at the
                    same time. This allows a switch to be faster than a hub.
                </p><p><span class="emphasis"><em>Router</em></span></p><p>
                    A router is used to make a connection between two
                    networks. Routers are also commonly used to connect a LAN
                    (local area network) to the Internet.
                </p></div><div class="sect2" title="Wireless"><div class="titlepage"><div><div><h3 class="title"><a name="idp37040"></a>Wireless</h3></div></div></div><p>
                    Some people may wish to try using LTSP in a wireless
                    environment, for various reasons.  This represents some
                    challenges.
                </p><p>
                    Wireless networks typically have more latency than wired
                    networks, which generally makes interactive programs feel
                    slow and unresponsive.  As well, wireless adaptors cannot
                    directly PXE boot, as you need to set things such as ESSID,
                    keys, etc., which wouldn't be there in a PXE capable card.
                </p><p>
                    However, for those wishing to use LTSP wirelessly, it is
                    still possible, but requires more hardware.  Wireless
                    bridge boxes are available, which contain both an ethernet
                    and a wireless network connection.  One can typically
                    connect to them like a small Internet router box, and
                    program them with the information pertinent to your
                    network.  You can then use a standard wired network card
                    connected directly to the bridge, and the bridge itself
                    will handle the wireless part.
                </p><p>
                    This method has been used with success by users of LTSP in
                    the past.  The latency of wireless makes the experience
                    slower, however, depending on the application you wish to
                    use, you may find it acceptible.
                </p></div></div><div class="sect1" title="Software"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp40560"></a>Software</h2></div></div></div><p>
                The most common network infrastructure services include:
            </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
                        DHCP (Dynamic Host Configuration Protocol)</p><p>
                        Each computer on a network needs a unique identifier
                        called an IP address. The IP address allows packets to be
                        directed to the computer, much like a street address
                        allows mail to be delivered to the correct house. An IP
                        address follows a specific form: four groups of digits
                        forming a number from 0 to 255. For example, a local IP
                        address might be 192.168.2.50.
                    </p><p>
                        For convenience, a computer's IP address can be given
                        by a server running the Dynamic Host Configuration
                        Protocol (DHCP) service. DHCP automatically provides
                        network settings to the computers on the network. With
                        DHCP, there is no need to keep track of each computer's
                        IP address.
                    </p></li><li class="listitem"><p>
                        DNS (Domain Name System)</p><p>
                        DNS is a service that runs on a server, and it is like a
                        phone book for computers, except that it stores IP
                        addresses instead of phone numbers. Your computer talks
                        to a DNS server every time you refer to another computer
                        system with a name instead of an IP address. For example:
                        www.ltsp.org, wikipedia.org, and google.com are all DNS
                        hostnames.
                    </p></li><li class="listitem"><p>
                        NTP (Network Time Protocol)
                    </p><p>
                        NTP is a service that runs on a server and allows other
                        computers to synchronize their clocks. The server
                        synchronizes with an extremely accurate atomic clock, and
                        then the clients synchronize with the server.
                    </p></li><li class="listitem"><p>
                        Web Server
                    </p><p>
                        A Web server answers queries using protocols such as
                        HTTP, and sends content such as web pages back to clients.
                        Your Web browser almost exclusively talks to Web servers.
                    </p></li><li class="listitem"><p>
                        Web Proxy
                    </p><p>
                        A Web proxy is a service that runs on a server and
                        accesses Web sites on behalf of the clients. A proxy can
                        cache some data to allow faster repeated access to
                        commonly accessed pages. This is not really needed in
                        essence for ltsp thin clients, since nothing runs on them,
                        it all runs on the server. But in order to allow for
                        content filtering, a proxy is required. In the case of a
                        mixed network, where some clients are independent from the
                        the thin client network, a proxy server is useful. The
                        most common and recommended proxy solution is called
                        Squid, which can be easily installed through your distro's
                        package manager.
                    </p></li><li class="listitem"><p>
                        Content Filter or Net Guardian
                    </p><p>
                        A typical network requires a filtering policy to be
                        implemented, which can easily be done by software like
                        dansguardian, squidguard or squid-filter. This allows an
                        administrator to block and control unwanted traffic like:
                    </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                                banner ads,
                            </p></li><li class="listitem"><p>
                                user behaviour tracking via cookies,
                            </p></li><li class="listitem"><p>
                                animated pictures,
                            </p></li><li class="listitem"><p>
                                JavaScript, VBScript, ActiveX (dangerous as well
                                as annoying).
                            </p></li></ol></div></li><li class="listitem"><p>
                        Firewall &amp; Port Blocker
                    </p><p>
                        A firewall is usually a service on the server, but often
                        DSL routers have the basic functionality of a firewall
                        too. A firewall can protect your server (and clients) by
                        restricting or allowing computers on the Internet from
                        initiating connections into your server or network. There
                        are many programs available for different distros. On
                        Ubuntu and Debian we recommend using gufw (uncomplicated
                        firewall), while Fedora has Fedora Firewall GUI, and SuSE
                        has Yast2 Firewall. If they are not already installed, you
                        can simply install them with your distro's package manager
                    </p></li></ul></div></div><div class="sect1" title="How LTSP Works"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp130464"></a>How LTSP Works</h2></div></div></div><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        LTSP is a collection of software that turns a normal
                        GNU/Linux installation into a terminal server. This allows
                        low-powered, low-cost thin-clients (or legacy hardware
                        you already own) to be used as terminals to the
                        thin-client server. LTSP is unique from other
                        thin-client systems in that it is considered by many
                        as the easiest to maintain. Other thin-client systems
                        require each client to have software that boots the
                        system to a point to be able to connect to the
                        terminal server. This could be a full-blown operating
                        system, or a minimal OS that simply provides an
                        interface to connect to the server. Systems such as
                        this generally require more maintenance and
                        administration, as the local software that boots the
                        thin-clients may become corrupt or contain bugs that
                        require attention. LTSP, on the other hand, requires
                        no client-side software. It requires only a PXE
                        capable network interface, which many thin-clients and
                        PCs have built-in already. This means that you need
                        absolutely no physical storage media (hard disk,
                        compact-flash, etc.) for your thin-client to boot to
                        LTSP. This significantly reduces the amount of
                        administration required to keep your network running.
                        The process of booting a thin-client to an LTSP server
                        is as follows:
                    </p></li><li class="listitem"><p>
                        Thin-clients boot via a protocol called PXE
                        (Pre-eXecution Environment)
                    </p></li><li class="listitem"><p>
                        PXE requests an IP address from a local DHCP
                        server
                    </p></li><li class="listitem"><p>
                        The DHCP server passes additional parameters to
                        the thin-client and downloads a Linux initramfs filesystem image
                        via TFTP into a RAM disk on the client itself.
                    </p></li><li class="listitem"><p>
                        The thin-client then boots the downloaded Linux
                        initramfs image, detects hardware, and connects to the LTSP
                        server's X session (normally handled by <a class="link" href="#ldm" title="Chapter 22. The LDM display manager">LDM</a>).
                    </p></li></ol></div><p>
                From here, all operations such as authenticating your
                username and password, launching applications, and viewing
                websites are actually handled on the LTSP server rather than
                the thin-client. The LTSP server transfers all graphical
                information to the thin-client over the network. This allows
                very low powered thin-clients to utilize the power of the
                server for all operations. It also allows for large client
                deployments with reduced overall resource utilization, as 50
                thin-clients all running the popular OpenOffice suite under
                different sessions generally only require enough RAM for a
                single instance of OpenOffice (excluding per-user
                configuration which is minimal). The server shares memory
                between user sessions, so libraries for applications are only
                loaded once and referenced for each user session.
            </p></div></div><div class="chapter" title="Chapter 3. LTSP Thin Client hardware requirements"><div class="titlepage"><div><div><h2 class="title"><a name="tc-hardware"></a>Chapter 3. LTSP Thin Client hardware requirements</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2866968">Hardware reuse and sizing</a></span></dt><dt><span class="sect1"><a href="#idp2869992">Clients</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2870312">Older hardware</a></span></dt><dt><span class="sect2"><a href="#idp2873288">CPU</a></span></dt><dt><span class="sect2"><a href="#idp2874936">Network</a></span></dt><dt><span class="sect2"><a href="#idp2879704">Thin client memory</a></span></dt><dt><span class="sect2"><a href="#idp2880608">Video Card</a></span></dt></dl></dd></dl></div><p>
            A lot of LTSP deployments are in classroom environments, and
            usually, in these situations, the primary goal is to re-use
            existing hardware that the school already owns. However,
            specifically designed thin clients can be used also.
        </p><div class="sect1" title="Hardware reuse and sizing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2866968"></a>Hardware reuse and sizing</h2></div></div></div><p>
                A person setting up a LTSP thin client environment for the
                first time, typically asks two questions:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        Will my existing machines work as terminals, or,
                        what should I buy to use as a terminal?
                    </p></li><li class="listitem"><p>
                        How big a server do I need?
                    </p></li></ol></div><p>
                Chances are, hardware that you already have is more than
                sufficient for terminals. One of the great advantages of an
                LTSP Server is that you can set up a high quality lab of
                terminals for your students to use, by leveraging the machines
                you already have. As for servers, usually, it's very easy to
                turn any high-end single user desktop machine into a terminal
                server capable of handling many thin clients. We'll present
                some guidelines that should help in making the most of your
                resources.
            </p></div><div class="sect1" title="Clients"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2869992"></a>Clients</h2></div></div></div><div class="sect2" title="Older hardware"><div class="titlepage"><div><div><h3 class="title"><a name="idp2870312"></a>Older hardware</h3></div></div></div><p>
                    There are three things to consider when trying to re-use
                    existing hardware:
                </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                            CPU
                        </p></li><li class="listitem"><p>
                            Network
                        </p></li><li class="listitem"><p>
                            Thin client memory
                        </p></li><li class="listitem"><p>
                            Video card
                        </p></li></ol></div></div><div class="sect2" title="CPU"><div class="titlepage"><div><div><h3 class="title"><a name="idp2873288"></a>CPU</h3></div></div></div><p>
                    For using the default, secure mode of LTSP, you'll need
                    to have a slightly faster CPU. Any 533 MHz or better CPU
                    should provide acceptable performance.
                </p><p>
                    If you have slower clients, in the range of 233 MHz to
                    533 MHz, you may be able to use them, if you're willing to
                    reduce the security of your thin client network. More
                    information on this is available in the chapter on
                    <a class="link" href="#ldm" title="Chapter 22. The LDM display manager">LDM</a>.
                </p></div><div class="sect2" title="Network"><div class="titlepage"><div><div><h3 class="title"><a name="idp2874936"></a>Network</h3></div></div></div><p>
                    A thin client boots over the network, using a small
                    program called a network boot loader. This network boot
                    loader is sometimes located on the card itself, or, for
                    older cards without one, the user can provide one on a
                    floppy or CDRom which can be used to boot the thin client.
                </p><p>
                    Three common network boot loaders which can be used are:
                </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                            <span class="emphasis"><em>PXE:</em></span> This one is the most
                            common, and many network cards and motherboards
                            with built-in network cards support this. If you
                            have one of these, you'll be able to boot without
                            any problems.
                        </p></li><li class="listitem"><p>
                            <span class="emphasis"><em>Etherboot/gPXE:</em></span> For older cards
                            that don't have PXE included on them, you can use
                            the Free Software equivalent, Etherboot, or it's
                            newer replacement, gPXE. This
                            excellent alternative to PXE can either be booted
                            from a floppy, memory stick, or CDRom, or, if
                            you're handy with electronics, be burned onto a
                            EPROM if your card has a socket for one. More
                            information on the project can be found at
                            http://www.etherboot.org, and you can download
                            ready-to-use Etherboot images at
                            http://www.rom-o-matic.org.
                        </p></li><li class="listitem"><p>
                            <span class="emphasis"><em>Yaboot:</em></span> For Macintosh PowerPC
                            machines (iMac's and later), you can use the built
                            in Yaboot network boot.
                        </p></li></ol></div></div><div class="sect2" title="Thin client memory"><div class="titlepage"><div><div><h3 class="title"><a name="idp2879704"></a>Thin client memory</h3></div></div></div><p>
                    The bare minimum for a thin client to work is about
                    48MB, but it will be unusably slow, so it is recommended
                    to install at least 128MB Ram, with 256MB Ram if you can
                    spare it. This will really help speed up thin clients.
                </p></div><div class="sect2" title="Video Card"><div class="titlepage"><div><div><h3 class="title"><a name="idp2880608"></a>Video Card</h3></div></div></div><p>
                    Typically, any video card that uses the PCI bus and has
                    16 MB or more of memory, should make a reasonable client.
                </p></div></div></div><div class="chapter" title="Chapter 4. LTSP Server requirements"><div class="titlepage"><div><div><h2 class="title"><a name="server-hardware"></a>Chapter 4. LTSP Server requirements</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2882432">Recommended specs</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2883712">Memory</a></span></dt><dt><span class="sect2"><a href="#idp2886592">Processors</a></span></dt><dt><span class="sect2"><a href="#idp2888904">Disks</a></span></dt></dl></dd></dl></div><p>
            An LTSP thin client network is quite scalable; a moderately
            powerful machine can serve several thin clients, and if you need
            to add more thin clients, you can either expand the capabilities
            of the existing server, or, simply add more servers.
        </p><div class="sect1" title="Recommended specs"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2882432"></a>Recommended specs</h2></div></div></div><p>
                Server sizing in an LTSP network is more art than science.
                Ask any LTSP administrator how big a server you need to use,
                and you'll likely be told "It depends". How big a server you
                need does depend largely on what it is you're planning on
                doing with your thin client network. The server requirements
                needed for a network where the only use will be a little light
                web-browsing, with no Java or Flash, will be greatly different
                from a network where you want to do heavy graphics,
                interactive games, and Flash animation. Here are some common
                guidelines that should fit most "average" cases.
            </p><div class="sect2" title="Memory"><div class="titlepage"><div><div><h3 class="title"><a name="idp2883712"></a>Memory</h3></div></div></div><p>
                    A GNU/Linux based operating system makes efficient use
                    of memory. The usual formula that's used for adding memory
                    to a thin client server is:
                </p><p>
                    256 + (192 * users) MB
                </p><p>
                    So, if your target is to have a server with 20
                    terminals, you'll need:
                </p><p>
                    256 + (192 * 20) = 256 + 3840 = 4096 MB
                </p><p>
                    So, you'll need 4 1 Gig memory sticks. Making sure
                    you've got enough memory is the single most important
                    thing you can do to help the performance of an LTSP thin
                    client server. If you do not have enough memory in your
                    server, you'll find your server will have to use the hard
                    drive as an overflow "virtual" memory. Hard drives are
                    much slower than memory, so you'll find things getting
                    very slow if this happens.
                </p><p>
                    If you intend to make heavy use of graphics work in your
                    curriculum, you may want to add even more, perhaps
                    doubling the previous estimate.
                </p></div><div class="sect2" title="Processors"><div class="titlepage"><div><div><h3 class="title"><a name="idp2886592"></a>Processors</h3></div></div></div><p>
                    How fast a processor you need is entirely dependant on
                    what programs you plan to use. Interactive games require a
                    bit more than say, a word processor. If you plan to use
                    Java and Flash plug-ins in your web browser, these can
                    consume a lot of processing power. For a "mixed" model,
                    i.e. some people playing TuxMath, a few people browsing
                    the web, and a few people typing in OpenOffice.org, a 2GHz
                    or better processor should be able to adequately handle 20
                    people with some minor delays. A 3GHz processor would be
                    better.
                </p><p>
                    For larger networks, moving to an SMP (Symmetric Multi
                    Processing), or multiple CPU server may be advantageous.
                    If you plan to handle 30 or more clients, a newer
                    dual-core Xeon server or dual-core Opteron will provide
                    good results.
                </p><p>
                    Remember, if you need to serve a large number of
                    clients, it will be worth your while to configure multiple
                    LTSP servers, each handling some of the terminals.
                </p></div><div class="sect2" title="Disks"><div class="titlepage"><div><div><h3 class="title"><a name="idp2888904"></a>Disks</h3></div></div></div><p>
                    It's advisable to use some form of RAID in the terminal
                    servers. Besides saving your data when a single disks
                    fails, it improves the performance (especially read
                    performance, which is the most common type of file
                    access). For people on a budget, setting up software RAID
                    1, with 2 SATA disks with NCQ (Native Command Queueing)
                    will provide good results. If you have a bigger budget,
                    and a bigger network, setting up your server with RAID 10
                    along with 10,000 RPM western digital VelociRaptors will
                    give you the best speeds possible. This will provide you
                    with top notch performance and reliability.
                </p></div></div></div><div class="chapter" title="Chapter 5. Network"><div class="titlepage"><div><div><h2 class="title"><a name="network"></a>Chapter 5. Network</h2></div></div></div><p>
            If you have more than 20 users, it is recommended to use Gigabit
            Ethernet connected to a gigabit port on a switch for your LTSP
            servers. Although normal usage ranges from 0.5 to 2mbit, clients
            can peak quite high (70mbit), especially when watching multimedia
            content.
        </p><p>
            Booting a thin client involves several steps. Understanding what
            is happening along the way will make it much easier to solve
            problems, should they arise.
        </p><p>
            There are four basic services required to boot an LTSP thin
            client. They are:
        </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                    DHCP
                </p></li><li class="listitem"><p>
                    TFTP
                </p></li><li class="listitem"><p>
                    NFS or NBD
                </p></li><li class="listitem"><p>
                    SSH
                </p></li></ol></div></div><div class="chapter" title="Chapter 6. The LTSP chroot environment"><div class="titlepage"><div><div><h2 class="title"><a name="chroot"></a>Chapter 6. The LTSP chroot environment</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2898912">The boot process of a thin client</a></span></dt></dl></div><p>
            In order to turn a computer into a thin client, we need to run a
            mini version of GNU/Linux on the workstation. It needs to boot
            this mini version of GNU/Linux over the network, since it probably
            won't have a hard drive on it's own. This mini GNU/Linux
            installation needs to live somewhere, and the best place for it is
            on the server.
        </p><p>
            This scaled-down GNU/Linux installation, customized so that
            it's efficient to boot over the network, is called a chroot
            environment. You can have several of them, based upon several
            different CPU architectures.
        </p><p>
            They'll normally live under <code class="filename">/opt/ltsp</code> on the server, with
            sub directories for each of the architectures. For instance, if you
            have a lab full of old Power PC Macs, and older PC's, you'll
            have an <code class="filename">/opt/ltsp/ppc</code> and an
            <code class="filename">/opt/ltsp/i386</code> directory on the
            server.
        </p><p>
            This is the LTSP project's preferred area to store the chroot,
            however, different distros that support LTSP are free to change
            this.  Check with your distro's specific LTSP documentation to see
            where the LTSP chroot is stored.
        </p><p>
            The reason why it is called a chroot environment is that to
            install it, the GNU/Linux command chroot is called to actually set
            the installation root to
            <code class="filename">/opt/ltsp/&lt;arch&gt;</code>. From there, a
            scaled-down version of the distribution is installed. What this
            means is that for you to manage the chroot, performing such things
            as updates, all you need to do is use the chroot command to change
            the root of your installation. Then you can use all your tools
            like you normally would.
        </p><div class="sect1" title="The boot process of a thin client"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2898912"></a>The boot process of a thin client</h2></div></div></div><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        Load the Linux kernel into the memory of the thin
                        client. This can be done several different ways,
                        including:
                    </p></li><li class="listitem"><p>
                        Each of the above booting methods will be explained
                        later in this chapter. But for now, it should be noted
                        that it makes sense in almost all cases to use a PXE
                        based network card during booting  for the fastest,
                        and easiest to setup method.
                    </p></li><li class="listitem"><p>
                        Once the kernel has been loaded into memory, it will
                        begin executing.
                    </p></li><li class="listitem"><p>
                        The kernel will initialize the entire system and all
                        of the peripherals that it recognizes.
                    </p></li><li class="listitem"><p>
                        This is where the fun really begins. During the
                        kernel loading process, an initramfs image will also
                        be loaded into memory.
                    </p></li><li class="listitem"><p>
                        Normally, when the kernel is finished booting, it will
                        launch the new task launcher <span class="command"><strong>upstart</strong></span>,
                        which will handle starting up a server or workstation.
                        But, in this case, we've instructed the kernel to load
                        a small shell script instead. This shell script is
                        called <span class="command"><strong>/init</strong></span>,and lives in the root
                        of the initramfs.
                    </p></li><li class="listitem"><p>
                        The <span class="command"><strong>/init</strong></span> script begins by mounting
                        <code class="filename">/proc</code> and
                        <code class="filename">/sys</code>, starts <span class="command"><strong>udev</strong></span> to
                        discover and initialize hardware, especially the
                        network card, which is needed for every aspect of the
                        boot from here on. As well, it creates a small ram
                        disk, where any local storage that is needed (to
                        configure the <code class="filename">xorg.conf</code> file, for
                        instance) can be written to.
                    </p></li><li class="listitem"><p>
                        The <span class="emphasis"><em>loopback</em></span> network interface is
                        configured. This is the networking interface that has
                        <span class="emphasis"><em>127.0.0.1</em></span> as its IP address.
                    </p></li><li class="listitem"><p>
                        A small DHCP client called <span class="command"><strong>ipconfig</strong></span>
                        will then be run, to make another query from the DHCP
                        server. This separate user-space query gets
                        information supplied in the dhcpd.conf file, like the
                        nfs root server, default gateway, and other important
                        parameters.
                    </p></li><li class="listitem"><p>
                        When <span class="command"><strong>ipconfig</strong></span> gets a reply from the
                        server, the information it receives is used to
                        configure the Ethernet interface, and determine the
                        server to mount the root from.
                    </p></li><li class="listitem"><p>
                        Up to this point, the root filesystem has been a ram
                        disk. Now, the <span class="command"><strong>/init</strong></span> script will
                        mount a new root filesystem via either NBD or NFS. In
                        the case of NBD, the image that is normally loaded is
                        <code class="filename">/opt/ltsp/images/&lt;arch&gt;.img</code>.
                        If the root is mounted via NFS, then the directory
                        that is exported from the server is typically
                        <code class="filename">/opt/ltsp/&lt;arch&gt;</code>.
                        It can't just mount the new filesystem as
                        <code class="filename">/</code>. It must
                        first mount it to a separate directory. Then, it will
                        do a <span class="command"><strong>run-init</strong></span>, which will swap the
                        current root filesystem for a new filesystem. When it
                        completes, the filesystem will be mounted on
                        <code class="filename">/</code>. At
                        this point, any directories that need to be writable
                        for regular start up to occur, like
                        <code class="filename">/tmp</code>, or <code class="filename">/var</code>, are
                        mounted at this time.
                    </p></li><li class="listitem"><p>
                        Once the mounting of the new root filesystem is
                        complete, we are done with the <span class="command"><strong>/init</strong></span> shell script and
                        we need to invoke the real <span class="command"><strong>/sbin/init</strong></span> program.
                    </p></li><li class="listitem"><p>
                        The <span class="command"><strong>init</strong></span> program will read the
                        <code class="filename">/etc/event.d</code>
                        directory and begin setting up the thin client
                        environment. From there, upstart will begin reading
                        the start up commands in <code class="filename">/etc/rcS.d</code>.
                    </p></li><li class="listitem"><p>
                        It will execute the <span class="command"><strong>ltsp-client-setup</strong></span> command
                        which will configure many aspects of the thin client environment,
                        such as checking if local devices need starting, loading any
                        specified modules, etc.
                    </p></li><li class="listitem"><p>
                        Next, the <span class="command"><strong>init</strong></span> program will begin
                        to execute commands in the <code class="filename">/etc/rc2.d</code> directory
                    </p></li><li class="listitem"><p>
                        One of the items in the <code class="filename">/etc/rc2.d</code>
                        directory is the <span class="command"><strong>ltsp-client-core</strong></span>
                        command that will be run while the thin client is
                        booting.
                    </p></li><li class="listitem"><p>
                        The <code class="filename">lts.conf</code> file will be parsed,
                        and all of the parameters in that file that pertain to
                        this thin client will be set as environment variables
                        for the <span class="command"><strong>ltsp-client-core</strong></span> script
                        to use.
                    </p></li><li class="listitem"><p>
                        If Sound is configured at this point, the
                        <span class="command"><strong>pulseaudio</strong></span>
                        daemon is started, to allow remote audio connections
                        from the server to connect and play on the thin
                        client.
                    </p></li><li class="listitem"><p>
                        If the thin client has local device support enabled,
                        the <span class="command"><strong>ltspfsd</strong></span> program is started to
                        allow the server to read from devices such as memory
                        sticks or CD-Roms attached to the thin client.
                    </p></li><li class="listitem"><p>
                        At this point, any of the screen sessions you've
                        defined in your <code class="filename">lts.conf</code> will be
                        executed.
                    </p><p>
                        Screen sessions are what you want to launch on all
                        of the virtual screens on your terminal. These are the
                        standard virtual screens that all GNU/Linux
                        distributions usually have, i.e.
                        <span class="keycap"><strong>Alt</strong></span>+<span class="keycap"><strong>F1</strong></span>, through
                        <span class="keycap"><strong>Alt</strong></span>+<span class="keycap"><strong>F10</strong></span>.
                    </p><p>
                        By default, a standard character based getty will be
                        run on screen 1 (<code class="varname">SCREEN_01</code> in the <code class="filename">lts.conf</code> file).
                    </p><p>
                        As well, if nothing else is specified in the
                        <code class="filename">lts.conf</code>
                        file, an <span class="command"><strong>ldm</strong></span>ldm; screen script is run
                        on <code class="varname">SCREEN_07</code>. The LTSP Display
                        Manager (<span class="command"><strong>ldm</strong></span>ldm;)
                        is the default login manager for LTSP.
                    </p></li><li class="listitem"><p>
                        If <code class="varname">SCREEN_07</code> is set to a value of
                        <span class="command"><strong>ldm</strong></span>ldm;, or <span class="command"><strong>startx</strong></span>, then the X
                        Windows System will be launched, giving you a graphical user interface.
                    </p><p>
                        By default, the Xorg server will auto-probe the card,
                        create a default <code class="filename">/etc/X11/xorg.conf</code> file on the
                        ram-disk in the terminal, and start up xorg with that custom config.
                    </p></li><li class="listitem"><p>
                        The X server will either start an encrypted <span class="command"><strong>ssh</strong></span>
                        tunnel to the server, in the case of <span class="command"><strong>ldm</strong></span>ldm;, or an an
                        XDMCP query to the LTSP server, in the case of
                        <span class="command"><strong>startx</strong></span>. Either way,
                        a login box will appear on the terminal.
                    </p></li><li class="listitem"><p>
                        At this point, the user can log in. They'll get a
                        session on the server.
                    </p><p>
                        This confuses a lot of people at first. They are
                        sitting at a thin client, but they are running a
                        session on the server. All commands they run will be
                        run on the server, but the output will be displayed on
                        the thin client.
                    </p></li></ol></div></div></div><div class="chapter" title="Chapter 7. Network booting the thin client"><div class="titlepage"><div><div><h2 class="title"><a name="network-boot"></a>Chapter 7. Network booting the thin client</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2937488">Boot ROM</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2938304">Etherboot</a></span></dt><dt><span class="sect2"><a href="#idp2940632">PXE</a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp2942904">Local media</a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp2943776">Floppy disk</a></span></dt><dt><span class="sect2"><a href="#idp2944832">Hard disk</a></span></dt><dt><span class="sect2"><a href="#idp2945696">CD-ROM</a></span></dt><dt><span class="sect2"><a href="#idp2946424">USB Memory device</a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp2947240">Installation</a></span></dt></dl></div><p>
            Getting the thin client to boot over the network can be
            accomplished in a variety of ways:
        </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                    Boot ROM
                </p></li><li class="listitem"><p>
                    Local media
                </p></li></ol></div><div class="sect1" title="Boot ROM"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2937488"></a>Boot ROM</h2></div></div></div><p>
                Depending on your network card, it may already contain a
                boot ROM, or you may be able to use an EPROM programmer to
                create your own. Check the hardware documentation for the
                network card in your thin client for details.
            </p><div class="sect2" title="Etherboot"><div class="titlepage"><div><div><h3 class="title"><a name="idp2938304"></a>Etherboot</h3></div></div></div><p>
                    Etherboot is a very popular open-source bootrom project.
                    It contains drivers for many common network cards, and
                    works very well with LTSP.
                </p><p>
                    ROM images suitable for booting from floppy, CD-ROM,
                    etc., can be obtained from http://www.rom-o-matic.org
                </p><p>
                    Linux kernels must be tagged with the <span class="command"><strong>mknbi-linux</strong></span>,
                    which will prepare the kernel for network booting, by
                    prefixing the kernel with some additional code, and
                    appending the initrd to the end of the kernel.
                </p><p>
                    The kernels that are supplied with LTSP are already
                    tagged, and ready to boot with Etherboot.
                </p></div><div class="sect2" title="PXE"><div class="titlepage"><div><div><h3 class="title"><a name="idp2940632"></a>PXE</h3></div></div></div><p>
                    Part of the 'Wired for Management' specification from the
                    late 1990's included a specification for a bootrom
                    technology known as the
                    <span class="emphasis"><em>Pre-boot Execution Environment</em></span>
                    commonly abbreviated as <span class="emphasis"><em>PXE</em></span>.
                </p><p>
                    A PXE bootrom can load at most a 32 kilo-byte file. A
                    Linux kernel is quite a bit larger than that. Therefore,
                    we setup PXE to load a 2nd stage boot loader called
                    <span class="command"><strong>pxelinux</strong></span>, which is small enough
                    to be loaded. It knows how to load
                    much larger files, such as a Linux kernel.
                </p></div></div><div class="sect1" title="Local media"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2942904"></a>Local media</h2></div></div></div><p>
                If your network card in the thin client doesn't have a boot
                ROM built in, and you don't have access to an EPROM burner,
                have no fear! Chances are, that old machine has a floppy
                drive, or CD-ROM in it. If so, then you can use local media to
                boot the thin client.
            </p><div class="sect2" title="Floppy disk"><div class="titlepage"><div><div><h3 class="title"><a name="idp2943776"></a>Floppy disk</h3></div></div></div><p>
                    Booting Etherboot from a floppy is an excellent way of
                    booting an LTSP thin client that doesn't have a boot ROM.
                    Etherboot is loaded in the boot sector of the floppy.
                    Then, it will act just like a bootrom. The boot code will
                    be executed, the network card will be initialized, and the
                    kernel will be loaded from the network server.
                </p></div><div class="sect2" title="Hard disk"><div class="titlepage"><div><div><h3 class="title"><a name="idp2944832"></a>Hard disk</h3></div></div></div><p>
                    The hard disk can be used with LILO or GRUB, to load the
                    Linux kernel and initrd. You can also load the Etherboot
                    bootrom image from the hard disk, and it will act like a
                    bootrom.
                </p></div><div class="sect2" title="CD-ROM"><div class="titlepage"><div><div><h3 class="title"><a name="idp2945696"></a>CD-ROM</h3></div></div></div><p>
                    A bootable CD-ROM can be loaded either with a Linux
                    kernel, or an Etherboot image.
                </p></div><div class="sect2" title="USB Memory device"><div class="titlepage"><div><div><h3 class="title"><a name="idp2946424"></a>USB Memory device</h3></div></div></div><p>
                    Just like a CD-ROM, Floppy disk and Hard disk, you can
                    use a USB Memory device to boot an Etherboot module.
                </p></div></div><div class="sect1" title="Installation"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2947240"></a>Installation</h2></div></div></div><p>
                With the integration of LTSP into distributions, installation
                of LTSP is now usually as easy as adding the LTSP packages in
                your distro's package manager.  Consult your distribution's
                documentation for details on how to install LTSP on your
                particular system.
            </p><p>
                However, as a general guideline, usually after you've installed
                your distributions' LTSP packages, and configured your network
                interfaces, and some kind of DHCP3 server, you'd run (as root):
            </p><pre class="screen">
sudo ltsp-build-client
            </pre><p>
                If you are on a 64-bit system but your clients
                have another architecture use the --arch option
                e.g. </p><pre class="screen">ltsp-build-client --arch i386</pre><p>
            </p><p>
                After that, you should be able to boot your first thin
                client.
            </p></div></div><div class="chapter" title="Chapter 8. Customizing thin client behaviour"><div class="titlepage"><div><div><h2 class="title"><a name="customizing-ltsconf"></a>Chapter 8. Customizing thin client behaviour</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2951280">Location of the lts.conf file</a></span></dt><dt><span class="sect1"><a href="#idp2953632">Sample lts.conf file</a></span></dt></dl></div><p>
            By default, most thin clients will automatically configure
            themselves correctly, and just work when they're plugged in.
            However, sometimes you may wish to customize their behaviour. You
            would do this by editing the <code class="filename">lts.conf</code> file.
        </p><div class="sect1" title="Location of the lts.conf file"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2951280"></a>Location of the lts.conf file</h2></div></div></div><p>
                In order to speed up LTSP, by default, we're using NBD
                (Network Block Devices) rather than NFS. To do this, we'd had
                to move the the lts.conf file out of the chroot and into the
                TFTP directory, in /var/lib/tftpboot/ltsp/&lt;arch&gt;, where
                &lt;arch&gt; is the architecture you are working on (usually i386,
                but could be something else, like amd64 for example). This
                means you can make changes to the file immediately, and simply
                reboot the terminal, without recompiling the image.
            </p></div><div class="sect1" title="Sample lts.conf file"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2953632"></a>Sample lts.conf file</h2></div></div></div><p>
                Here is an example of the lts.conf file: </p><pre class="screen">
################
# Global defaults for all clients
# if you refer to the local server, just use the
# "server" keyword as value
# see lts_parameters.txt for valid values
################

[default]
    X_COLOR_DEPTH=16
    LOCALDEV=True
    SOUND=True
    NBD_SWAP=True
    SYSLOG_HOST=server
    XKBLAYOUT=de

################
#[MAC ADDRESS]: Per thin client settings
################

[00:11:25:84:CE:BA]
    XSERVER = vesa
    X_MOUSE_DEVICE=/dev/ttyS0
    X_MOUSE_PROTOCOL=intellimouse

###############
# A Thin Client Print server
# (switch off X by pointing tty7 to shell,
# to save ressources)
###############

[00:11:25:93:CF:00]
    PRINTER_0_DEVICE=/dev/usblp0
    SCREEN_07=shell

###############
# A workstation that executes a specific
# command after login
###############

[00:11:25:93:CF:02]
    LDM_SESSION=/usr/bin/myloginscript
            </pre></div></div><div class="chapter" title="Chapter 9. Format of the lts.conf file"><div class="titlepage"><div><div><h2 class="title"><a name="lts-conf"></a>Chapter 9. Format of the lts.conf file</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2958520">Section headings </a></span></dt><dt><span class="sect1"><a href="#idp2960384">Variable Assignments</a></span></dt><dt><span class="sect1"><a href="#idp2962184">The LIKE keyword</a></span></dt></dl></div><p>
            When LTSP was designed, one of the issues that needed to be
            dealt with was varying hardware configurations for the thin
            client. Certainly, whatever combination of processor, network card
            and video card available today would not be available in 3 months,
            when you want to add more thin clients to the network. So, LTSP
            devised a way of specifying the configuration of each thin client.
            The configuration file is called lts.conf and it lives in the
            <code class="filename">/var/lib/tftpboot/ltsp/&lt;arch&gt;/</code> directory.
        </p><p>
            The format of the lts.conf allows for 'default' settings and
            individual thin client settings. If all of your thin clients are
            identical, you could specify all of the configuration settings in
            the <code class="varname">'[Default]'</code> section. The file must have a first line
            containing <code class="varname">'[Default]'</code> in any case.
        </p><div class="sect1" title="Section headings"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2958520"></a>Section headings </h2></div></div></div><p>
                Section headings begin with an identifier in the form
                [Default] which is used for all computers as mentioned above,
                and [MAC address] for individual workstations, in the form of
                [XX:XX:XX:XX:XX:XX], where X is the digits 0-9, or A-F.
            </p><p>
                You can usually read the MAC address for a network card from
                a sticker on the card itself, or use some kind of network tool
                to discover it. The best way to check for the MAC address of
                the machine is by starting it up, checking its IP number and
                doing a <span class="command"><strong>arp -an</strong></span> on the server, this should then tell you
                which IP number has which MAC address.
            </p></div><div class="sect1" title="Variable Assignments"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2960384"></a>Variable Assignments</h2></div></div></div><p>
                After the section heading, you can then define variables.
                Variables are ether boolean values, requiring a True/False or
                Y/N answer. Note that you can either use True or False, Yes or
                No, or Y or N. Whichever you prefer. Other variables may
                simply be strings, supplied after the = sign. The general
                format of an assignment looks like:
            </p><pre class="screen">
VARIABLE = value
            </pre><p>
                Comments can be inserted into the file for your
                documentation purposes. Comments start with a # character, and
                everything after the # for the rest of the line is considered
                a comment.
            </p></div><div class="sect1" title="The LIKE keyword"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2962184"></a>The LIKE keyword</h2></div></div></div><p>
                The <code class="varname">LIKE</code> keyword allows you to define a
                general set of parameters under a unique identifier, and then
                assign individual workstations that set of parameters using the
                <code class="varname">LIKE</code> keyword.  An example will illustrate
                it's use.
            </p><p>Let's assume you have 3 kinds of thin clients on your
                network.  One set, which are used in the lab, have older video
                cards, and must use 16 bit colour at 1024x768 resolution.
                Another set need to have their video ram set to 8 megs, and a
                third set which auto-detect everything correctly.  We don't
                need to specify anything for the third set, but having some
                symbolic names for the first two would help us to maintain the
                <code class="filename">lts.conf</code> file.
            </p><p>
                Here's an example <code class="filename">lts.conf</code> that
                illustrates how this would be done:
            </p><pre class="screen">
[Lab]
    X_COLOR_DEPTH = 16
    X_MODE_0 = 1024x768

[Lowram]
    X_VIDEO_RAM = 8096

[00:40:32:71:77:A1]
    LIKE = Lab

[00:70:84:BB:27:52]
    LIKE = Lowram
            </pre><p>
                As you can see, using the <code class="varname">LIKE</code> keyword can
                make your <code class="filename">lts.conf</code> more readable, by
                allowing you to group related parameters together into a single
                symbolic name.
            </p></div></div><div class="chapter" title="Chapter 10. General thin client parameters"><div class="titlepage"><div><div><h2 class="title"><a name="general-parms"></a>Chapter 10. General thin client parameters</h2></div></div></div><p>
            There are several variables that one can define in the lts.conf
            file which control how the thin client interacts with the server.
            These are:
        </p><div class="variablelist"><a name="lts-conf-general-list"></a><dl><dt><span class="term"><code class="varname">CONFIGURE_FSTAB</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>True</em></span></p><p>/etc/fstab is generated by boot scripts</p></dd><dt><span class="term"><code class="varname">FSTAB_0..FSTAB_9</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Complete lines to add to /etc/fstab, for example:</p><pre class="screen">
FSTAB_1="server:/home    /home           nfs     defaults,nolock 0       0"
 </pre></dd><dt><span class="term"><code class="varname">CRONTAB_01..CRONTAB_10</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>A crontab line to add for a thin client.</p></dd><dt><span class="term"><code class="varname">DNS_SERVER</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>A valid IP for domain name server Used to build the client's
          resolv.conf file. Not needed by default.</p></dd><dt><span class="term"><code class="varname">SEARCH_DOMAIN</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>sets a valid search domain in the clients's resolv.conf file.
          Used to build the resolv.conf file. Not needed by default.</p><p>Needed if <code class="varname">DNS_SERVER</code> is set</p></dd><dt><span class="term"><code class="varname">HOSTNAME</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This parameter sets the host name for the thin client, for
          situations when if no DNS is available. A hostname is auto-generated
          if no hostname is set.</p></dd><dt><span class="term"><code class="varname">HOSTNAME_BASE</code></span></dt><dd><p>string, default <span class="emphasis"><em>ltsp</em></span></p><p>This parameter sets the base for the autogenerated host name
          for the thin client.</p></dd><dt><span class="term"><code class="varname">HOSTNAME_EXTRA</code></span></dt><dd><p>string, default <span class="emphasis"><em>ip</em></span></p><p>This parameter determines weather autogenerated host names are
          appended with information based on the ip address or mac address.
          Values are "ip" or "mac".</p></dd><dt><span class="term"><code class="varname">NBD_SWAP</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Set this to <span class="command"><strong>True</strong></span> if you want to turn on NBD
          swap.</p><p>If unspecified, it's automatically enabled for thin clients
          with less than 300 MB RAM and for fat clients with less than 800 MB
          RAM.</p></dd><dt><span class="term"><code class="varname">NBD_SWAP_PORT</code></span></dt><dd><p>integer, default <span class="emphasis"><em>10809</em></span></p><p>The port on which NBD swapping will occur. An nbd-server
          export named <code class="varname">swap</code> is normally used.</p></dd><dt><span class="term"><code class="varname">NBD_SWAP_SERVER</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>SERVER</em></span></p><p>The NBD swap server can exist on any server on the network
          that is capable of handling it. You can specify the IP address of
          that server. The default is whatever the value of
          <code class="varname">SERVER</code> set to.</p></dd><dt><span class="term"><code class="varname">NBD_SWAP_THRESHOLD</code></span></dt><dd><p>integer, default <span class="emphasis"><em>300</em></span></p><p>Automatically enable <code class="varname">NBD_SWAP</code> if the client
          has less RAM than the specified. For FAT clients, it defaults to
          800.</p></dd><dt><span class="term"><code class="varname">RM_SYSTEM_SERVICES</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>A space separated list of services that shouldn't start on the
          clients even if they're installed, for example:</p><pre class="screen">RM_SYSTEM_SERVICES="apache2 dnsmasq mysql nbd-server nfs-kernel-server"</pre></dd><dt><span class="term"><code class="varname">RM_THIN_SYSTEM_SERVICES</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Same as <code class="varname">RM_SYSTEM_SERVICES</code>, but it only
          affects thin clients.</p></dd><dt><span class="term"><code class="varname">KEEP_SYSTEM_SERVICES</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Some services are deleted by default when an LTSP client
          boots, either to save RAM, or because they don't make sense for
          netbooted machines. If you need some of them you can list them in
          <code class="varname">KEEP_SYSTEM_SERVICES</code>, for example:</p><pre class="screen">KEEP_SYSTEM_SERVICES="acpid avahi-daemon bluetooth cups"</pre></dd><dt><span class="term"><code class="varname">SERVER</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>unset</em></span></p><p>This is the server that is used for the
          <code class="varname">XDM_SERVER</code>, <code class="varname">TELNET_HOST</code>,
          <code class="varname">XFS_SERVER</code> and <code class="varname">SYSLOG_HOST</code>, if
          any of those are not specified explicitly. If you have one machine
          that is acting as the server for everything, then you can just
          specify the address here and omit the other server parameters. If
          this value is not set, it will be auto detected as the machine that
          the thin client booted from.</p></dd><dt><span class="term"><code class="varname">SYSLOG_HOST</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>unset</em></span></p><p>If you want to send logging messages to a machine other than
          the default server, then you can specify the machine here. If this
          parameter is NOT specified, then it will use the
          <code class="varname">SERVER</code> parameter described above. Starting from
          LTSP 5.4.1 and on, this parameter must be specified to enable remote
          logging.</p><p>You have to configure your server to accept remote logging as
          well.</p></dd><dt><span class="term"><code class="varname">USE_LOCAL_SWAP</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>If you have a hard drive installed in the thin client, with a
          valid swap partition on it, this parameter will allow the thin
          client to swap to the local hard drive.</p></dd><dt><span class="term"><code class="varname">TIMEZONE</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>The timezone code for the thin client to use.</p></dd><dt><span class="term"><code class="varname">TIMESERVER</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>unset</em></span></p><p>The address of an NTP time server that the thin client can set
          it's time from. If unset, the thin client just uses the BIOS
          time.</p></dd><dt><span class="term"><code class="varname">SHUTDOWN_TIME</code></span></dt><dd><p>string, format hh:mm:ss in 24 hour format, default
          <span class="emphasis"><em>unset</em></span></p><p>Time at which thin client will automatically shut down.</p></dd><dt><span class="term"><code class="varname">LTSP_FATCLIENT</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>unset</em></span></p><p>Enable Fat Client support. It's automatically enabled if any
          sessions exist in /usr/share/xsessions.</p></dd><dt><span class="term"><code class="varname">FAT_RAM_THRESHOLD</code></span></dt><dd><p>integer, default <span class="emphasis"><em>300</em></span></p><p>Disable fat client support if less RAM is present.</p></dd></dl></div></div><div class="chapter" title="Chapter 11. Local Device thin client parameters"><div class="titlepage"><div><div><h2 class="title"><a name="localdev-parms"></a>Chapter 11. Local Device thin client parameters</h2></div></div></div><p>
            Local devices such as USB sticks, CD-ROM drives, or even floppy
            disks need special configuration in order to be accessed from the
            thin client. The following values allow to enable or disable the
            use of various local devices:
        </p><div class="variablelist"><a name="lts-conf-localdev-list"></a><dl><dt><span class="term"><code class="varname">LOCALDEV</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>True</em></span></p><p>This parameter enables local devices support, like CD's and
          USB sticks. Users plugging them in should see them on the desktop,
          after they've been allowed to access the FUSE subsystem on the
          server. Check your distibutions docs to see how this is done on your
          distribution.</p></dd><dt><span class="term"><code class="varname">LOCALDEV_DENY_CD</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>This parameter disables local device support for CD and
          DVD-rom devices.</p></dd><dt><span class="term"><code class="varname">LOCALDEV_DENY_FLOPPY</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>This parameter disables local device support for floppy
          devices.</p></dd><dt><span class="term"><code class="varname">LOCALDEV_DENY_INTERNAL_DISKS</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>True</em></span></p><p>This parameter disables local device support for internal ATA
          and SCSI hard disk devices.</p></dd><dt><span class="term"><code class="varname">LOCALDEV_DENY_USB</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>This parameter disables local device support for USB
          devices.</p></dd><dt><span class="term"><code class="varname">LOCALDEV_DENY</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This parameter disables local device support for devices
          matching certain patterns. Values are specified as a comma-separated
          list of sysfs attributes, which can be obtained by using udevadm
          info (or udevinfo). for example: </p><pre class="screen">
                        udevadm info -q env -n /dev/hda
                        ID_TYPE=disk
                        ID_BUS=ata
                        </pre><p> should return a list of the attributes
          relevent to /dev/hda. to exclude this disk and disks like it using
          LOCALDEV_DENY: LOCALDEV_DENY="ID_BUS:ata+ID_TYPE:disk" would match
          devices that were on the ata bus that were disks.</p></dd></dl></div></div><div class="chapter" title="Chapter 12. Screen Scripts"><div class="titlepage"><div><div><h2 class="title"><a name="screen-scripts"></a>Chapter 12. Screen Scripts</h2></div></div></div><p>
            Screen scripts are how LTSP determines what type of login will
            run on what virtual screen. Most GNU/Linux machines have 12
            virtual consoles, which you can access by pressing
            <span class="keycap"><strong>Control</strong></span>+<span class="keycap"><strong>Alt</strong></span>+<span class="keycap"><strong>F1</strong></span>, through
            <span class="keycap"><strong>Control</strong></span>+<span class="keycap"><strong>Alt</strong></span>+<span class="keycap"><strong>F12</strong></span>.
            On some distributions there is a text based getty that is
            started on screen 1, but you normally can't log into it, as there
            are no local users on the thin client.
        </p><p>
            However, for debugging purposes, you may want to set up root to
            log in on the thin client. You may need to do this if you're
            debugging problems with local devices, for example. Fortunately,
            it's easy to do: on the server, as root, just chroot into the LTSP chroot,
            and set the password with passwd.
        </p><pre class="screen">
chroot /opt/ltsp/&lt;arch&gt;
passwd
        </pre><p>
            By default, if there's nothing else mentioned in
            <code class="filename">lts.conf</code>,
            an LDM session will be started on screen 7.
        </p><div class="variablelist"><a name="lts-conf-screen-list"></a><dl><dt><span class="term"><code class="varname">SCREEN_01...SCREEN_12</code></span></dt><dd><p>string, default <span class="emphasis"><em>ldm</em></span></p><p>Up to 12 screen scripts can be specified for a thin client.
          This will give you up to 12 sessions on the thin client, each
          accessible by pressing the Ctrl-Alt-F1 through Ctrl-Alt-F12
          keys.</p><p>Currently, possible values include: kiosk, ldm, menu, rdesktop
          (deprecated), shell, ssh, startx (deprecated), telnet, xdmcp,
          xfreerdp, xterm</p><p>Look in the
          <code class="filename">$CHROOT/usr/share/ltsp/screen.d</code> directory for
          more scripts, or write your own, and put them there.</p></dd><dt><span class="term"><code class="varname">TELNET_HOST</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>unset</em></span></p><p>If the thin client is setup to have a character based
          interface, then the value of this parameter will be used as the host
          to telnet into. If this value is NOT set, then it will use the value
          of <code class="varname">SERVER</code> above.</p></dd></dl></div></div><div class="chapter" title='Chapter 13. The "rdesktop" screen script'><div class="titlepage"><div><div><h2 class="title"><a name="rdesktop"></a>Chapter 13. The "rdesktop" screen script</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2975632">Single Line</a></span></dt><dt><span class="sect1"><a href="#idp2978088">Multiple Line</a></span></dt><dt><span class="sect1"><a href="#idp2980056">RDP + Local Devices</a></span></dt><dt><span class="sect1"><a href="#idp2984840">RDP + Local Sound</a></span></dt></dl></div><p>
            LTSP includes an <span class="command"><strong>rdesktop</strong></span> screen script that
            can be used to bring up a full screen RDP connection using
            <span class="command"><strong>rdesktop</strong></span> on the thin client. This
            screen script can be invoked in one of two ways.
        </p><div class="sect1" title="Single Line"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2975632"></a>Single Line</h2></div></div></div><p>
                For example, by adding the following
                <code class="filename">lts.conf</code> parameter:
            </p><pre class="screen">
SCREEN_07 = "rdesktop -a 16 192.168.0.253"
            </pre><p>
                That is, calling it with the arguments you normally would on the
                command line. This method of invocation is useful in that you can have
                multiple screens pointing to different RDP servers with different
                arguments and switch between them.
            </p></div><div class="sect1" title="Multiple Line"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2978088"></a>Multiple Line</h2></div></div></div><p>
                For example, by adding the following parameters to
                <code class="filename">lts.conf</code>:
            </p><pre class="screen">
SCREEN_07 = rdesktop
RDP_SERVER = 192.168.0.253
RDP_OPTIONS = "-a 16"
            </pre><p>
                This method will apply the same arguments and server to all screens.
            </p></div><div class="sect1" title="RDP + Local Devices"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2980056"></a>RDP + Local Devices</h2></div></div></div><p>
                When you run an <span class="command"><strong>rdesktop</strong></span> screen script,
                <span class="command"><strong>rdesktop</strong></span> runs on the thin
                client. The thin client, by default, has no way of automounting
                removable devices, and the normal localdev approach used in an
                <span class="command"><strong>ldm</strong></span>ldm; session in which local devices invoke a call over ssh to have the
                Linux server mount the device obviously won't work.
            </p><p>
                To address this issue in a controlled way, we have chosen to use
                <span class="command"><strong>ltspfs</strong></span> as a local automounter for RDP
                sessions. To add local device support, you must:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        Install ltspfs in the chroot.
                    </p></li><li class="listitem"><p>
                        Use folder redirection in <span class="command"><strong>rdesktop</strong></span> to map the local /media/root
                        folder created by ltspfs to the server as a shared drive.  For
                        example, you could add the following <span class="command"><strong>rdesktop</strong></span> argument:
                    </p><pre class="screen">
-r disk:Drives=/media/root
                    </pre><p>
                        With this redirection, you should get a "Drives" share in Windows
                        under My Computer. Inside the "Drives" share, a folder will appear for
                        each local device.  The local device will be mounted with ltspfs, so
                        they can just be removed when the device is not being written to
                        without "unmounting".
                    </p></li></ol></div></div><div class="sect1" title="RDP + Local Sound"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2984840"></a>RDP + Local Sound</h2></div></div></div><p>
                You should be able to add sound to your RDP session with the following
                <span class="command"><strong>rdesktop</strong></span> argument:
            </p><pre class="screen">
-r sound:local
            </pre></div></div><div class="chapter" title="Chapter 14. Modules and startup scripts"><div class="titlepage"><div><div><h2 class="title"><a name="modules-scripts"></a>Chapter 14. Modules and startup scripts</h2></div></div></div><p>
            For the most part, LTSP does a very good job of detecting what
            hardware's on your thin client. However, it's possible that you
            may want to manually specify a kernel module to load after boot.
            Alternatively, you may have a script you've written that you've
            put in the chroot, and want to make sure gets run at startup. LTSP
            provides some hooks to allow you to do this.
        </p><div class="variablelist"><a name="lts-conf-modules-list"></a><dl><dt><span class="term"><code class="varname">MODULE_01...MODULE_10</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Up to 10 kernel modules can be loaded by using these
          configuration entries. The entire command line that you would use
          when running insmod can be specified here. For example:</p><pre class="screen">
MODULE_01 = uart401.o
MODULE_02 = "sb.o io=0x220 irq=5 dma=1"
MODULE_03 = opl3.o
                    </pre><p>If the value of this parameter is an absolute path name, then
          <span class="command"><strong>insmod</strong></span> will be used to load the module.
          Otherwise, <span class="command"><strong>modprobe</strong></span> will be used.</p><p>In normal circumstances, you shouldn't need to specify
          anything here, as most hardware will be auto-detected.</p></dd><dt><span class="term"><code class="varname">RCFILE_01...RCFILE_10</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Commands to be executed from
          <code class="filename">/etc/rc.local</code> when the client boots.</p></dd></dl></div></div><div class="chapter" title="Chapter 15. Sound in LTSP"><div class="titlepage"><div><div><h2 class="title"><a name="sound"></a>Chapter 15. Sound in LTSP</h2></div></div></div><p>
            Sound in LTSP is handled by running the
            <span class="command"><strong>pulseaudio</strong></span> daemon on the
            thin client, which sits on top of the ALSA kernel drivers.  The
            thin client's kernel should detect the thin client sound hardware
            via the usual udev mechanisms, and enable the sound card.  At boot
            time, the <span class="command"><strong>pulseaudio</strong></span> daemon is run, which allows the thin client to
            receive audio streams via network connections.
        </p><p>
            On login, the LDM sets both the <code class="varname">PULSE_SERVER</code> and
            <code class="varname">ESPEAKER</code>
            environment variables for the X windows session, to allow the
            server to re-route the sound over a TCP/IP socket to the thin
            client.
        </p><div class="variablelist"><a name="lts-conf-sound-list"></a><dl><dt><span class="term"><code class="varname">SOUND</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>True</em></span></p><p>This parameter enables sound for the thin client.</p></dd><dt><span class="term"><code class="varname">SOUND_DAEMON</code></span></dt><dd><p>string, default <span class="emphasis"><em>pulse</em></span></p><p>This parameter sets which sound daemon to use on the thin
          client. Values are esd, nasd, and pulse (default).</p></dd><dt><span class="term"><code class="varname">VOLUME</code></span></dt><dd><p>integer, default <span class="emphasis"><em>90</em></span></p><p>This represents an integer percentage of the volume, ranging
          from 0 to 100%.</p></dd><dt><span class="term"><code class="varname">HEADPHONE_VOLUME</code></span></dt><dd><p>integer, default <span class="emphasis"><em>unset</em></span></p><p>This represents an integer percentage of the headphone volume,
          ranging from 0 to 100%.</p></dd><dt><span class="term"><code class="varname">PCM_VOLUME</code></span></dt><dd><p>integer, default <span class="emphasis"><em>unset</em></span></p><p>This represents an integer percentage of the PCM volume,
          ranging from 0 to 100%.</p></dd><dt><span class="term"><code class="varname">CD_VOLUME</code></span></dt><dd><p>integer, default <span class="emphasis"><em>unset</em></span></p><p>This represents an integer percentage of the CD input volume,
          ranging from 0 to 100%.</p></dd><dt><span class="term"><code class="varname">FRONT_VOLUME</code></span></dt><dd><p>integer, default <span class="emphasis"><em>unset</em></span></p><p>This represents an integer percentage of the front speaker
          volume, ranging from 0 to 100%.</p></dd><dt><span class="term"><code class="varname">MIC_VOLUME</code></span></dt><dd><p>integer, default <span class="emphasis"><em>unset</em></span></p><p>This represents an integer percentage of the microphone input
          volume, ranging from 0 to 100%.</p></dd></dl></div></div><div class="chapter" title="Chapter 16. X-Windows parameters"><div class="titlepage"><div><div><h2 class="title"><a name="xwin-parms"></a>Chapter 16. X-Windows parameters</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2994168">X.org Configuration</a></span></dt></dl></div><p>
            Setting up X windows on the thin client's normally a pretty easy
            operation. The thin client uses X.org's own auto configuration
            mode to let X determine what it thinks is installed in the box.
        </p><p>
            However, sometimes, this doesn't always work. Either due to
            strange/buggy hardware, or buggy drivers in X.org, or because X
            detects default settings that you don't want. For instance, it may
            detect that your monitor is capable of doing 1280x1024, but you'd
            prefer it to come up in 1024x768 resolution. Fortunately, you can
            tweak individual X settings, or, alternatively, simply provide
            your own <code class="filename">xorg.conf</code> to use.
        </p><div class="sect1" title="X.org Configuration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2994168"></a>X.org Configuration</h2></div></div></div><div class="variablelist"><a name="lts-conf-xorg-list"></a><dl><dt><span class="term"><code class="varname">USE_XFS</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Instructs the thin client to look at the
          <code class="varname">XFS_SERVER</code> option, and use XFS for serving
          fonts.</p></dd><dt><span class="term"><code class="varname">XFS_SERVER</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>unset</em></span></p><p>If you are using an X Font Server to serve fonts, then you can
          use this entry to specify the IP address of the host that is acting
          as the font server. If this is not specified, it will use the
          default server, which is specified with the
          <code class="varname">SERVER</code> entry described above.</p></dd><dt><span class="term"><code class="varname">CONFIGURE_X</code></span></dt><dd><p>If you want to be able to configure the individual settings of
          the X configuration file, without having the X automatically
          configure the graphics card for you, you must enable this option. By
          default this option is turned off. To turn it on do: </p><pre class="screen">CONFIGURE_X = True</pre><p>You
          don't need this option just for keyboard and mouse settings. It
          corresponds to the graphic card and monitor options only.</p></dd><dt><span class="term"><code class="varname">X_CONF</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>If you want to create your own complete X.org config file, you
          can do so and place it in the
          <code class="filename">/opt/ltsp/&lt;arch&gt;/etc/X11</code> directory. Then,
          whatever you decide to call it needs to be entered as a value for
          this configuration variable. For example: X_CONF =
          /etc/X11/my-custom-xorg.conf Note that for the thin client, you
          reference it from <code class="filename">/etc/X11</code>.</p></dd><dt><span class="term"><code class="varname">X_RAMPERC</code></span></dt><dd><p>default '100', Percentage of RAM for X server</p><p>Some programs allocate a large amount of ram in the X.org
          server running on your thin client. Programs like
          <span class="command"><strong>Firefox</strong></span> and <span class="command"><strong>Evince</strong></span> can use up
          so much ram, that they eventually exhaust all your physical ram, and
          NBD swap, causing your thin client to crash. If you find your
          clients being booted back to a login prompt, or freezing up when
          viewing certain PDF's or web pages, this may be the problem.</p><p>The <code class="varname">X_RAMPERC</code> variable stands for X RAM
          PERCent, and is a number between 0 and 100 that specifies how much
          of the free space on your thin client X.org is allowed to consume.
          You'll generally want to set it at something lower than 100 percent,
          if you're having problems. Experimentation has shown a value between
          80 and 90 will usually keep the terminal alive. What will then
          happen is the program consuming the memory will die, as opposed to
          the thin client itself. If you're having unexplained terminal
          problems, specifying:</p><p>X_RAMPERC = 80</p><p>in your <code class="filename">lts.conf</code> file may improve
          things.</p></dd><dt><span class="term"><code class="varname">X_VIRTUAL</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>If you want to have a virtual screen which is larger than the
          physical screen on your thin client, you would configure that by
          providing a string of the form "width height" in this parameter,
          similar to the <code class="filename">xorg.conf</code> format.</p></dd><dt><span class="term"><code class="varname">XDM_SERVER</code></span></dt><dd><p>IP address, default <span class="emphasis"><em>unset</em></span></p><p>If you're using the older <span class="command"><strong>startx</strong></span> screen
          script, and need to specify a different XDMCP server, then you can
          specify the server here. If this parameter is NOT specified, then it
          will use the <code class="varname">SERVER</code> parameter described
          above.</p></dd><dt><span class="term"><code class="varname">XSERVER</code></span></dt><dd><p>You can use this parameter to override which X server the thin
          client will run. For PCI and AGP video cards, this parameter should
          not be required. The thin client should normally be able to
          auto-detect the card.</p><p>If, for some reason you do need to manually set it, here are
          some valid values:</p><p>ark, ati, atimisc, chips, cirrus_alpine cirrus, cirrus_laguna,
          cyrix, dummy, fbdev fglrx, glint, i128, i740, i810, imstt, mga,
          neomagic, newport, nsc, nv, r128, radeon, rendition, riva128, s3,
          s3virge, savage, siliconmotion, sis, sisusb, tdfx, tga, trident,
          tseng, v4l, vesa, vga, via, vmware, voodoo</p></dd><dt><span class="term"><code class="varname">X_MOUSE_DEVICE</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This is the device node that the mouse is connected to. If it
          is a serial mouse, this would be a serial port, such as
          <code class="filename">/dev/ttyS0</code> or <code class="filename">/dev/ttyS1</code>.
          This is not needed for PS/2 or USB mice, as they are
          auto-detected.</p></dd><dt><span class="term"><code class="varname">X_MOUSE_PROTOCOL</code></span></dt><dd><p>Should be auto-detected. However, valid entries
          include:</p><p>sunkbd, lkkbd, vsxxxaa, spaceorb, spaceball, magellan,
          warrior, stinger, mousesystems, sunmouse, microsoft, mshack,
          mouseman, intellimouse, mmwheel, iforce, h3600ts, stowawaykbd,
          ps2serkbd, twiddler, twiddlerjoy</p></dd><dt><span class="term"><code class="varname">X_MOUSE_EMULATE3BTN</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>unset</em></span></p><p>Normally unset, may need to be set to <span class="emphasis"><em>Y</em></span>
          for certain 2 button mice.</p></dd><dt><span class="term"><code class="varname">X_NUMLOCK</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>If this variable is set to <span class="emphasis"><em>True</em></span>, then the
          numlock key will be defaulted to on when the terminal boots. Note
          that the <span class="command"><strong>numlockx</strong></span> command must be installed in
          the chroot for this to work.</p></dd><dt><span class="term"><code class="varname">X_COLOR_DEPTH</code></span></dt><dd><p>Integer: 2, 4, 8, 16, 24, 32 default
          <span class="emphasis"><em>unset</em></span></p><p>This is the number of bits to use for the colour depth.
          Possible values are <span class="command"><strong>8</strong></span>, <span class="command"><strong>16</strong></span>,
          <span class="command"><strong>24</strong></span> and <span class="command"><strong>32</strong></span>. 8 bits will give
          256 colours, 16 will give 65536 colours, 24 will give 16 million
          colours and 32 bits will give 4.2 billion colours! Not all X servers
          support all of these values. The default for thin clients is 16 in
          order to minimize network bandwidth, while for fat clients the X
          server default is used.</p></dd><dt><span class="term"><code class="varname">X_SMART_COLOR_DEPTH</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>True</em></span></p><p>If set, thin clients no longer default to 16 bit colour depth
          but use the X server default instead.</p></dd><dt><span class="term"><code class="varname">X_HORZSYNC</code></span></dt><dd><p>min-max values</p><p>This sets the X.org <span class="command"><strong>HorizSync</strong></span> configuration
          parameter. This should be auto-detected for your monitor, however,
          if you want to force a lower resolution, use this parameter to do
          so.</p></dd><dt><span class="term"><code class="varname">X_VERTREFRESH</code></span></dt><dd><p>min-max values</p><p>This sets the X.org <span class="command"><strong>VertRefresh</strong></span>
          configuration parameter. This should be auto-detected for your
          monitor. If you need to force a lower resolution, use this parameter
          to do so.</p></dd><dt><span class="term"><code class="varname">X_VIDEO_RAM</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This sets the X.org <span class="command"><strong>VideoRam</strong></span> configuration
          parameter. The setting is in kilobytes. This should be auto-detected
          for your monitor. If you need to force a different video ram
          setting, use this parameter to do so.</p></dd><dt><span class="term"><code class="varname">X_OPTION_01...X_OPTION_12</code></span></dt><dd><p>A valid Device option</p><p>This allows you to specify <span class="command"><strong>Option</strong></span> settings
          in the <code class="filename">xorg.conf</code> file, to add options to the
          video driver. A common use for this will be to test turning off
          acceleration in your driver, if you're having trouble. An example
          usage would be:</p><pre class="screen">
X_OPTION_01 = "\"NoAccel\"" X_OPTION_02 = "\"AnotherOption\" \"True\""
                    </pre><p>You probably won't need these except in special
          circumstances.</p></dd><dt><span class="term"><code class="varname">X_MONITOR_OPTION_01...X_MONITOR_OPTION_10</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>A valid Monitor option, that would normally be used in an
          xorg.conf file.</p></dd><dt><span class="term"><code class="varname">X_MODE_0</code>, <code class="varname">X_MODE_1</code>, and
        <code class="varname">X_MODE_2</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>These set the X.org <code class="varname">ModeLine</code> configuration.
          For example, if your thin client comes up in a higher resolution
          than what you want, say, 1280x1024, specifying:</p><pre class="screen">
X_MODE_0 = 1024x768
                    </pre><p>should get your desired resolution on startup.</p><p>X_MODE_* require XRANDR_DISABLE=True to work. For drivers that
          support XRANDR, the XRANDR_MODE_* variabled are preferred. See the
          XRANDR section.</p></dd><dt><span class="term"><code class="varname">X_BLANKING</code></span></dt><dd><p>A positive integer</p><p>When set, <code class="varname">X_BLANKING</code> will cause DPMS
          standby to activate after the number of seconds provided. If the
          monitor does not support DPMS, then the blanking screensaver will
          activate. If <code class="varname">X_BLANKING</code> is set to 0, the monitor
          will remain on indefinitely. NOTE: This does not apply to the
          <span class="command"><strong>xdmcp</strong></span> or <span class="command"><strong>startx</strong></span> screen script.
          Also, server-side Xclients such as power managers and screensavers
          may override this setting.</p></dd></dl></div></div></div><div class="chapter" title="Chapter 17. XRANDR setting for managing displays"><div class="titlepage"><div><div><h2 class="title"><a name="xrandr"></a>Chapter 17. XRANDR setting for managing displays</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp2996304">New Xorg structure within LTSP</a></span></dt><dt><span class="sect1"><a href="#idm9104">Script structure</a></span></dt><dt><span class="sect1"><a href="#idm3504">XRandR parameters</a></span></dt></dl></div><p>
            The new Xorg Xserver has the ability to figure out (for the most part,
            to the extent that the driver helps in the process) the best mode for
            the videocard.  Moreover, with the new dependency upon hal and Xrandr,
            it is recommended to add input devices with hal and modify video modes
            with Xrandr 1.2 calls.  In essence, the xorg.conf becomes a place really
            to fix deficiencies in poorly written drivers or to force certain
            abnormal driver behavior in a particular environment in a way that can
            not be otherwise done through hal or Xrandr.
        </p><div class="sect1" title="New Xorg structure within LTSP"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp2996304"></a>New Xorg structure within LTSP</h2></div></div></div><p>
                To accommodate this, Xorg now understands partial xorg.conf files.
                Meaning you only add the sections that you need to force.  Otherwise, it
                discovers everything.  That's why you might see minimalist xorg.conf
                files in your LTSP chroot.
            </p><p>
                The <code class="filename">screen-session.d/</code> directory (located in the
                chroot's <code class="filename">/usr/share/ltsp directory</code>) is a structure of shell scripts all
                of which are sourced in order (similar to
                <code class="filename">Xsession.d/</code> or <code class="filename">rc.d/</code> that you
                may be familiar with).  These scripts are executed upon the beginning of
                each session but before the Xserver (if the session runs an Xserver) is
                launched.  You can make whatever script you want that may need to run at
                that point.  For LTSP, one thing we use it for is to set up
                <span class="emphasis"><em>how</em></span> the
                Xserver will be launched.  This entails not just generating a
                <code class="filename">xorg.conf</code>
                file as needed, but also configuring the parameters that the Xserver
                should be launched with.  The nice thing about a collection of sourced
                scripts is that it gives flexibility to the distribution or to the
                administrator to add additional scripts that may be required for that
                distribution or for a particular network environment that will not
                modify existing files (and therefore require more maintenance to care
                for updates in the upstream code).
            </p></div><div class="sect1" title="Script structure"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idm9104"></a>Script structure</h2></div></div></div><p>
                Each script is named with a prefix letter, then an order number, then a
                name.  The prefix letter determines when the scripts of that prefix are
                executed and the order number determines in what order.
            </p><p>
                PREFIXES:
                Prefixes that may be used include:
            </p><p>
                S - Is a script that runs at the beginning of a session (screen script)
                K - Is a script that runs at the end of a session (screen script)
                XS - Is a script that is only run at the beginning of screen scripts
                that run an Xserver
            </p><p>
                All of the scripts that generate a xorg.conf or modify the Xserver
                arguments are XS* scripts.
            </p><p>
                These scripts are mostly organized by the particular lts.conf parameter
                or function that they affect.  For example, XS85-xvideoram adds the
                ability to specify the X_VIDEO_RAM parameter in lts.conf and force the
                amount of video ram used by the driver.
            </p><p>
                If you are going to create your own script, I recommend looking at other
                scripts to understand the structure.  Since many hacks may impact the
                same xorg.conf sections, each section has a function of hacks assigned
                to it, and in your script, you would create a function and add it to the
                list of functions for that section.  For example, if you add something
                to the Monitor section (that cannot already be added through existing
                functions) you would create a function in your script and add it to the
                monitor_hacks function list.  Again, easier to read the code and look at
                examples to understand how to write a new script.
            </p><p>
                Also, please note that one of the lts.conf parameters you can specify
                is:  <code class="varname">CONFIGURE_X_COMMAND</code>
                This should be set to a path to a script.  So, if you have the old
                configure-x.sh and like it better, simply copy it into the chroot, to
                say,
                <span class="command"><strong>/opt/ltsp/&lt;arch&gt;/usr/share/ltsp/configure-x.sh</strong></span>
                and then in <code class="filename">lts.conf</code>,
                specify:  </p><pre class="screen">CONFIGURE_X_COMMAND =
                    "/usr/share/ltsp/configure-x.sh"</pre><p>  and
                you will be back to where you were.
            </p></div><div class="sect1" title="XRandR parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idm3504"></a>XRandR parameters</h2></div></div></div><div class="variablelist"><a name="lts-conf-xrandr-list"></a><dl><dt><span class="term"><code class="varname">XRANDR_COMMAND_0 ... XRANDR_COMMAND_9</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Full xrandr command to run when X starts. They're useful to
          define and add custom modes, for example:</p><pre class="screen">
XRANDR_COMMAND_0="xrandr --newmode 1024x600 49.00 1024 1072 1168 1312 600 603 613 624 -hsync +vsync"
XRANDR_COMMAND_1="xrandr --addmode VGA1 1024x600"
XRANDR_COMMAND_2="xrandr --output VGA1 --mode 1024x600"
 </pre><p>You can use <span class="command"><strong>cvt</strong></span> to find the correct timings for
          new modes.</p></dd><dt><span class="term"><code class="varname">XRANDR_DISABLE</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Disables XRANDR output handling so that the older
          <code class="varname">X_MODE_0</code> way of setting resolution works. This is
          useful on older Xorg drivers that don't support XRANDR.</p></dd><dt><span class="term"><code class="varname">XRANDR_OUTPUT_0 ... XRANDR_OUTPUT_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Define xrandr output - can also be used for multihead
          positioning</p></dd><dt><span class="term"><code class="varname">XRANDR_MODE_0 ... XRANDR_MODE_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Valid video mode resolution. Sets mode for corresponding
          output.</p></dd><dt><span class="term"><code class="varname">XRANDR_NEWMODE_0 ... XRANDR_NEWMODE_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Specifies a valid modeline for a corresponding output.</p></dd><dt><span class="term"><code class="varname">XRANDR_RATE_0 ... XRANDR_RATE_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Sets refresh rate for the corresponding output.</p></dd><dt><span class="term"><code class="varname">XRANDR_DPI_0 ... XRANDR_DPI_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Sets the DPI for the corresponding output.</p></dd><dt><span class="term"><code class="varname">XRANDR_ROTATE_0 ... XRANDR_ROTATE_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Sets the rotation for the corresponding output.</p></dd><dt><span class="term"><code class="varname">XRANDR_REFLECT_0 ... XRANDR_REFLECT_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Sets the reflection for the corresponding output.</p></dd><dt><span class="term"><code class="varname">XRANDR_SIZE_0 ... XRANDR_SIZE_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Sets the resolution for the corresponding output (for xrandr
          &lt;1.2).</p></dd><dt><span class="term"><code class="varname">XRANDR_ORIENTATION_0 ...
        XRANDR_ORIENTATION_8</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Sets the orientation for the corresponding output (for xrandr
          &lt;1.2).</p></dd></dl></div></div></div><div class="chapter" title="Chapter 18. Printer configuration parameters"><div class="titlepage"><div><div><h2 class="title"><a name="printer"></a>Chapter 18. Printer configuration parameters</h2></div></div></div><p>
            Sometimes, it's convenient to hang a printer off of a thin
            client in a lab, so that the computer lab has access to local
            printing resources. Fortunately, LTSP can accommodate printing on
            the workstation.
        </p><p>
            LTSP can connect up to 3 printers per workstation to the network
            via a small daemon called JetPipe. Both parallel and USB printers
            are supported. JetPipe makes the printer look like a standard HP
            Jet Direct printer interface. You can then create any cups printer
            on your server, and point it at the printer via a Jet Direct
            connection.
        </p><p>
            In your <code class="filename">dhcpd.conf</code> file that controls your
            thin client IP assignments, you'll want to assign a static IP for
            the terminal with the printers, to guarantee that it gets the same
            IP address every time it boots. Otherwise, your printing won't
            work if the terminal leases a different IP address.
        </p><div class="variablelist"><a name="lts-conf-printer-list"></a><dl><dt><span class="term"><code class="varname">PRINTER_0_DEVICE</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>The device name of the printer. Valid device names such as
          <code class="filename">/dev/lp0</code>, or <code class="filename">/dev/usblp0</code>
          are allowed.</p></dd><dt><span class="term"><code class="varname">PRINTER_0_PORT</code></span></dt><dd><p>integer, default <span class="emphasis"><em>9100</em></span></p><p>The TCP/IP Port number to use for the print server.</p></dd><dt><span class="term"><code class="varname">PRINTER_0_TYPE</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Can either be set to P (for parallel), U (for USB) or S (for
          serial). Autodetected in most cases (except for serial).</p></dd><dt><span class="term"><code class="varname">PRINTER_0_WRITE_ONLY</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Some parallel printers may need this set in order for the thin
          client to communicate to them properly. If you have problems with a
          parallel printer only printing part of the print job, try setting
          this to <span class="emphasis"><em>True</em></span>.</p></dd><dt><span class="term"><code class="varname">PRINTER_0_SPEED</code></span></dt><dd><p>integer, default <span class="emphasis"><em>9600</em></span></p><p>Should be set to the baud rate of the printer (serial printers
          only).</p></dd><dt><span class="term"><code class="varname">PRINTER_0_FLOWCTRL</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Should be set to the flow control desired for the printer
          (serial printers only).</p></dd><dt><span class="term"><code class="varname">PRINTER_0_PARITY</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Specifies whether parity should be enabled for the printer
          (serial printers only).</p></dd><dt><span class="term"><code class="varname">PRINTER_0_DATABITS</code></span></dt><dd><p>integer, default <span class="emphasis"><em>8</em></span></p><p>Specifies how many data bits for the printer (serial printers
          only).</p></dd><dt><span class="term"><code class="varname">PRINTER_0_OPTIONS</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Specifies specific options for the printer (serial printers
          only).</p></dd><dt><span class="term"><code class="varname">LDM_PRINTER_LIST</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Comma separated list of printers that will be displayed for
          that thin client (requires patched cups, included in Debian and
          Ubuntu).</p></dd><dt><span class="term"><code class="varname">LDM_PRINTER_DEFAULT</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Default printer for the thin client.</p></dd><dt><span class="term"><code class="varname">SCANNER</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>unset</em></span></p><p>This parameter enables scanners for the thin client.</p></dd></dl></div></div><div class="chapter" title="Chapter 19. Keyboard parameters"><div class="titlepage"><div><div><h2 class="title"><a name="keyboard"></a>Chapter 19. Keyboard parameters</h2></div></div></div><p>
            All of the keyboard support files are copied into the
            <code class="filename">/opt/ltsp/&lt;arch&gt;</code> hierarchy, so configuring international keyboard
            support is simply a matter of configuring X.org. There are several
            configuration parameters for this.
        </p><p>
            The values for the above parameters are from the X.org
            documentation. Whatever is valid for X.org is valid for these
            parameters.
        </p><p>
            We would like to add documentation to show what values are
            needed for each type of international keyboard. If you work with
            this and can configure your international keyboards, feedback to
            LTSP would be greatly appreciated.
        </p><div class="variablelist"><a name="lts-conf-keyboard-list"></a><dl><dt><span class="term"><code class="varname">CONSOLE_KEYMAP</code></span></dt><dd><p>A valid console keymap, default <span class="emphasis"><em>en</em></span></p><p>Allows you to specify a valid console keymap for TELNET_HOST
          sessions.</p></dd><dt><span class="term"><code class="varname">XKBLAYOUT</code></span></dt><dd><p>A valid xkb layout, default <span class="emphasis"><em>unset</em></span></p><p>Consult the X.org documentation for valid settings.</p></dd><dt><span class="term"><code class="varname">XKBMODEL</code></span></dt><dd><p>A valid xkb model, default <span class="emphasis"><em>unset</em></span></p><p>Consult the X.org documentation for valid settings.</p></dd><dt><span class="term"><code class="varname">XKBVARIANT</code></span></dt><dd><p>A valid xkb variant, default <span class="emphasis"><em>unset</em></span></p><p>Consult the X.org documentation for valid settings.</p></dd><dt><span class="term"><code class="varname">XKBRULES</code></span></dt><dd><p>A valid xkb rules specifier, default
          <span class="emphasis"><em>unset</em></span></p><p>Consult the X.org documentation for valid settings.</p></dd><dt><span class="term"><code class="varname">XKBOPTIONS</code></span></dt><dd><p>A valid xkb options specifier, default
          <span class="emphasis"><em>unset</em></span></p><p>Consult the X.org documentation for valid settings.</p></dd></dl></div></div><div class="chapter" title="Chapter 20. Touchscreen configuration"><div class="titlepage"><div><div><h2 class="title"><a name="touchscreen"></a>Chapter 20. Touchscreen configuration</h2></div></div></div><p>
            Description to be added later.
        </p><div class="variablelist"><a name="lts-conf-touchscreen-list"></a><dl><dt><span class="term"><code class="varname">USE_TOUCH</code></span></dt><dd><p>Enable touchscreen</p><p>default &lt;unset&gt;, Enable touchscreen</p><div class="informaltable"><table border="0"><colgroup><col><col><col><col></colgroup><tbody><tr><td>X_TOUCH_DEVICE</td><td>Path to device</td><td>/dev/ttyS0</td><td>set device for touchscreen</td></tr><tr><td>X_TOUCH_DRIVER</td><td>Touchscreen driver</td><td>elographics</td><td>set driver for touchscreen</td></tr><tr><td>X_TOUCH_MAXX</td><td>integer</td><td>3588</td><td>Xmax</td></tr><tr><td>X_TOUCH_MAXY</td><td>integer</td><td>3526</td><td>Ymax</td></tr><tr><td>X_TOUCH_MINX</td><td>integer</td><td>433</td><td>Xmin</td></tr><tr><td>X_TOUCH_MINY</td><td>integer</td><td>569</td><td>Ymin</td></tr><tr><td>X_TOUCH_UNDELAY</td><td>integer</td><td>10</td><td>Untouch delay</td></tr><tr><td>X_TOUCH_RTPDELAY</td><td>integer</td><td>10</td><td>Repeat touch delay</td></tr></tbody></table></div></dd></dl></div></div><div class="chapter" title="Chapter 21. Local Applications"><div class="titlepage"><div><div><h2 class="title"><a name="localapps"></a>Chapter 21. Local Applications</h2></div></div></div><p>
            Description to be added later.
        </p><div class="variablelist"><a name="lts-conf-localapps-list"></a><dl><dt><span class="term"><code class="varname">LOCAL_APPS</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>True</em></span></p><p>Enables support for running local apps on the thin
          client.</p></dd><dt><span class="term"><code class="varname">LOCAL_APPS_EXTRAMOUNTS</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This parameter enables extra mount points to be mounted on the
          thin client with sshfs. This require a commas separated list of
          directory.</p></dd><dt><span class="term"><code class="varname">LOCAL_APPS_MENU</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Enables overriding of menu items from remote (server)
          applications. If this is set to <span class="emphasis"><em>True</em></span>, local
          applications in the users menu will be used instead of the
          applications on the server.</p></dd><dt><span class="term"><code class="varname">LOCAL_APPS_MENU_ITEMS</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This item should contain a comma separated list of application
          names as they appear on their .desktop files.</p></dd><dt><span class="term"><code class="varname">LOCAL_APPS_WHITELIST</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Used to allow only specified space-separated commands to be
          run as local apps, allow all is default if unset. Full-paths are
          required for each command. No spaces in the names are
          allowed.</p></dd></dl></div></div><div class="chapter" title="Chapter 22. The LDM display manager"><div class="titlepage"><div><div><h2 class="title"><a name="ldm"></a>Chapter 22. The LDM display manager</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp3023368">Introduction</a></span></dt><dt><span class="sect1"><a href="#idp3028048">Theory of operation</a></span></dt><dt><span class="sect1"><a href="#idp3036008">Encrypted versus unencrypted sessions</a></span></dt><dt><span class="sect1"><a href="#idp3038048">Auto login features</a></span></dt><dt><span class="sect1"><a href="#idp3039912">Load balancing features</a></span></dt><dt><span class="sect1"><a href="#idp3041328">RC script capabilities</a></span></dt><dt><span class="sect1"><a href="#idp3054464">LDM lts.conf parameters</a></span></dt><dt><span class="sect1"><a href="#idp3055304">Multiple server setup</a></span></dt></dl></div><div class="sect1" title="Introduction"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3023368"></a>Introduction</h2></div></div></div><p>
                The LTSP Display Manager, or <span class="command"><strong>ldm</strong></span>ldm; is the
                display manager specifically written by the LTSP project to
                handle logins to a GNU/Linux server. It is the default display
                manager for LTSP thin clients running under LTSP, and has a
                lot of useful features:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        It is written in C, for speed and efficiency on low
                        end clients.
                    </p></li><li class="listitem"><p>
                        It supports logging in via either a greeter (a
                        graphical login application) or autologin.
                    </p></li><li class="listitem"><p>
                        It can be configured to encrypt X Windows traffic,
                        for increased security, or leave it unencrypted, for
                        better performance on slower clients.
                    </p></li><li class="listitem"><p>
                        It contains a simple load-balancing system, to allow
                        the system administrator to allow load balancing
                        across several servers.
                    </p></li></ol></div><p>
                We'll go over the <code class="filename">lts.conf</code> entries you'll
                need to control these features below.
            </p></div><div class="sect1" title="Theory of operation"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3028048"></a>Theory of operation</h2></div></div></div><p>
                To help understand the following sections, a bit of an
                explanation of how <span class="command"><strong>ldm</strong></span>ldm; does it's work is
                needed. Most thin client display managers tend to run up on
                the server. The <span class="command"><strong>ldm</strong></span>ldm; display manager is
                unique in that it runs on the thin client itself. This allows
                the thin client to have a lot of choice as to how it will set
                up the connection. A typical login session goes as follows:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        <span class="command"><strong>ldm</strong></span>ldm; launches and starts up the X
                        Windows display on the thin client.
                    </p></li><li class="listitem"><p>
                        <span class="command"><strong>ldm</strong></span>ldm; starts up the greeter, which is
                        a graphical program which presents the user with a
                        nice login display and allows them to select their
                        session, language, and host they'd like to log into.
                    </p></li><li class="listitem"><p>
                        <span class="command"><strong>ldm</strong></span>ldm; collects the information from
                        the greeter, and starts an ssh session with the
                        server. This ssh connection is used to create an ssh
                        master socket, which is used by all subsequent
                        operations.
                    </p></li><li class="listitem"><p>
                        Now, the users selected session is started via the
                        master socket. Depending on whether or not an
                        encrypted connection has been requested, via the
                        <code class="varname">LDM_DIRECTX</code> parameter, the session is either connected
                        back to the local display via the ssh tunnel, or via a
                        regular TCP/IP connection.
                    </p></li><li class="listitem"><p>
                        During the session, any memory sticks, or other
                        local devices that are plugged in, communicate their
                        status to the server via the ssh control socket.
                    </p></li><li class="listitem"><p>
                        When the user exits the session, the ssh connection is
                        closed down, the X server is stopped, and <span class="command"><strong>ldm</strong></span>ldm;
                        restarts itself, so everything starts with a clean slate.
                    </p></li></ol></div></div><div class="sect1" title="Encrypted versus unencrypted sessions"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3036008"></a>Encrypted versus unencrypted sessions</h2></div></div></div><p>
                By default, LTSP5 encrypts the X session between the server.
                This makes your session more secure, but at the cost of
                increased processing power required on the thin client and on
                the server. If processing power is a concern to you, it's very
                easy to specify that the connection for either an individual
                workstation, or the default setting should use an unencrypted
                connection. To do so, simply specify:
            </p><pre class="screen">
LDM_DIRECTX = True
            </pre><p>
                in your <code class="filename">lts.conf</code> file in the appropriate
                section.
            </p></div><div class="sect1" title="Auto login features"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3038048"></a>Auto login features</h2></div></div></div><p>
                This new version of LDM supports auto login of accounts, if
                specified in the <code class="filename">lts.conf</code> file. Simply
                create a config section for each of the terminals you want to
                log in automatically (you can use either MAC address, IP
                address, or hostname) and specify the variable
                <code class="varname">LDM_USERNAME</code>
                and <code class="varname">LDM_PASSWORD</code>. Note that you must have
                created these accounts on the server, with the passwords
                specified. An example will serve to illustrate how to use
                this:
            </p></div><div class="sect1" title="Load balancing features"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3039912"></a>Load balancing features</h2></div></div></div><p>
                In this version of LTSP, there's a simple load-balancing
                solution implemented that allows administrators to have
                multiple LTSP servers on the network, and allow the thin
                client to pick which one of the servers it would like to log
                into.
            </p><p>
                The host selection system is simple and flexible enough to
                allow administrators to implement their own policy on how they
                want the load balancing to happen: either on a random,
                load-based, or round robin system. See for details.
            </p></div><div class="sect1" title="RC script capabilities"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3041328"></a>RC script capabilities</h2></div></div></div><p>
                LDM has a very good system for handling user-supplied rc.d
                scripts.  This allows people looking to add site-specific
                customizations to their LTSP setups an easy way to integrate
                this functionality into LTSP.
            </p><p>
                These rc.d scripts can be placed in
                <code class="filename">$CHROOT/usr/share/ldm/rc.d/</code>.  They are
                executed in the usual rc.d type method, so you must make sure
                that any script you write will not make a call to
                <span class="command"><strong>exit</strong></span>.
            </p><p>
                The files start with the letter I, S, K, or X, and have two
                digits after them, allowing you to place them in order of
                execution.  The letters stand for:
            </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
                        <span class="emphasis"><em>I</em></span> scripts are executed at the
                        start of LDM, before the greeter has been presented.
                    </p></li><li class="listitem"><p>
                        <span class="emphasis"><em>S</em></span> scripts are executed after the user
                        has logged in, but before the X session is run.
                    </p></li><li class="listitem"><p>
                        <span class="emphasis"><em>X</em></span> scripts are executed while the X
                        session is being executed.
                    </p></li><li class="listitem"><p>
                        <span class="emphasis"><em>K</em></span> scripts are executed after the X
                        session has ended, but before the user logs out entirely.
                    </p></li></ul></div><p>
                Your scripts can make use of the following environment
                variables in the S, X, and K scripts:
            </p><div class="variablelist"><dl><dt><span class="term"><code class="varname">LDM_USERNAME</code></span></dt><dd><p>
                            This is the username the user supplied at login.
                        </p></dd><dt><span class="term"><code class="varname">LDM_SOCKET</code></span></dt><dd><p>
                            The path to the ssh control socket that LDM has open
                            for communication with the server.
                        </p></dd><dt><span class="term"><code class="varname">LDM_SERVER</code></span></dt><dd><p>
                            The current server that LDM is connected to.
                        </p></dd><dt><span class="term"><code class="varname">LDMINFO_IPADDR</code></span></dt><dd><p>
                            The IP address of the thin client.
                        </p></dd></dl></div><p>
                You can use these variables to create scripts that customize
                behaviors at login time.  For instance, lets say you were
                running the GNOME desktop environment, and wanted to force your
                users to have blank-only mode for their screen savers, to save
                network bandwidth.
            </p><p>
                Since the script is actually running <span class="emphasis"><em>on the thin
                    client itself</em></span>, you want this script to set this
                up on the server, where the Gnome session is running.  That's
                where you can make use of the <code class="varname">LDM_SOCKET</code> and
                <code class="varname">LDM_SERVER</code> environment variables to run an
                <span class="command"><strong>ssh</strong></span> command on the server, using the control
                socket that LDM has set up.  Here's an example script.  You
                could install this into
                <code class="filename">$CHROOT/usr/share/ldm/rc.d/X01-set-blankonly</code>:
            </p><pre class="screen">
#
# sourced with .
#
# Script to automatically switch gnome screensaver to blank
# only mode
#
ssh -S ${LDM_SOCKET} ${LDM_SERVER} "/usr/bin/gconftool-2 --set --type string /apps/gnome-screensaver/mode blank-only"
            </pre><p>
                Using this mechanism, it's easy to customize your LTSP setup to
                your needs.
            </p></div><div class="sect1" title="LDM lts.conf parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3054464"></a>LDM lts.conf parameters</h2></div></div></div><div class="variablelist"><a name="lts-conf-ldm-list"></a><dl><dt><span class="term"><code class="varname">LDM_AUTOLOGIN</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>This option allows the thin client to login automatically
          without the need for a username and password. To set it set </p><pre class="screen">LDM_AUTOLOGIN = True</pre><p>
          for the corresponding thin client. This will attempt to log in the
          thin client with username = hostname and password = hostname. You
          can also set a user and password with
          <code class="varname">LDM_USERNAME</code> and <code class="varname">LDM_PASSWORD</code>
          variables.</p></dd><dt><span class="term"><code class="varname">LDM_DEBUG_TERMINAL</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Opens a local terminal after login for debugging
          purposes.</p></dd><dt><span class="term"><code class="varname">LDM_DIRECTX</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>This is arguably the most important LDM option, as it allows
          you to turn off the encrypted X tunnel via SSH, and instead run a
          less secure, but much faster unencrypted tunnel. Users who have
          slower thin clients will want to set this to
          <span class="emphasis"><em>True</em></span>. It is set to <span class="emphasis"><em>True</em></span> by
          default in Fedora.</p></dd><dt><span class="term"><code class="varname">LDM_GUESTLOGIN</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>This option places a GUEST LOGIN button underneath the entry
          field for username and password. To set it set </p><pre class="screen">LDM_GUESTLOGIN = True</pre><p>
          for the corresponding thin client. You can also set a user and
          password with </p><pre class="screen">LDM_USERNAME = John</pre><p> and </p><pre class="screen">LDM_PASSWORD = secret</pre><p>,
          although not setting these will default to the hostname of the thin
          client.</p></dd><dt><span class="term"><code class="varname">LDM_GUEST_SERVER</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This is a space-separated list of available servers where
          guest logins are available. The first server in the list will be the
          default guest login server unless the user selects another from the
          preferences menu at login time.</p></dd><dt><span class="term"><code class="varname">LDM_USER_ALLOW</code></span></dt><dd><p>string</p><p>This option allows you to give access to certain thin clients
          based on the username set in <code class="filename">/etc/passwd</code>. For
          example, thin client A should only be used by Jane, Bob, and Fred,
          while thin client B is to be used by Harry only. By adding these
          options to the corresponding mac addresses you allow or deny access
          to the thin clients in question. Example:</p><pre class="screen">
[thin:client:A:mac:address]
LDM_USER_ALLOW = Jane,Bob,Fred
[thin:client:B:mac:adddress]
LDM_USER_ALLOW = Harry
                   </pre></dd><dt><span class="term"><code class="varname">LDM_LOGIN_TIMEOUT</code></span></dt><dd><p>integer</p><p>This lets LDM automatically login after the set amount of time
          in seconds. If you specify this option, then do not specify
          LDM_AUTOLOGIN. Use it in this format:</p><pre class="screen">
[thin:client:mac:address]
LDM_LOGIN_TIMEOUT = 25
                    </pre><p>Note that you will need to also set LDM_GUESTLOGIN=True for
          LDM_LOGIN_TIMEOUT to be useful.</p></dd><dt><span class="term"><code class="varname">LDM_USERNAME</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This is the username that LDM will use for autologin.</p></dd><dt><span class="term"><code class="varname">LDM_PASSWORD</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This is the password that LDM will use for autologin.</p></dd><dt><span class="term"><code class="varname">LDM_SYSLOG</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Normally, LDM logs to a simple file on the thin client, namely
          <code class="filename">/var/log/ldm.log</code>. This has the advantage of
          being fast, but the disadvantage of being hard to read for the
          administrator in the event of a problem, as the administrator must
          either spawn a shell screen session, or enable root login in tty1.
          By setting this option to "True", you can log up to the server
          <span class="emphasis"><em>if you've enabled your server's syslog for remote
          logging.</em></span></p></dd><dt><span class="term"><code class="varname">LDM_SERVER</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This is a space-separated list of available servers for LDM to
          log into. The first server in the list will be the default server
          unless the user selects another from the preferences menu at login
          time.</p></dd><dt><span class="term"><code class="varname">LDM_LANGUAGE</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>This allows the system administrator to override the default
          locale settings on the server by setting the environment variables
          LANG, LANGUAGE and LC_ALL at login.</p><p>Use the LANG variable to set the default locale for LDM's user
          interface.</p></dd><dt><span class="term"><code class="varname">LDM_FORCE_LANGUAGE</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Same as <code class="varname">LDM_LANGUAGE</code>, but it overrides any
          previously user selected language and it even hides the LDM language
          selection menu.</p></dd><dt><span class="term"><code class="varname">LDM_SSHOPTIONS</code></span></dt><dd><p>string</p><p>Allows you to specify custom options to the ssh sessions
          started between LDM and the server.</p></dd><dt><span class="term"><code class="varname">SSH_OVERRIDE_PORT</code></span></dt><dd><p>integer, default <span class="emphasis"><em>unset</em></span></p><p>If you run your ssh server different from the defult, you may
          set the port the thin client will use with this parameter.</p></dd><dt><span class="term"><code class="varname">SSH_FOLLOW_SYMLINKS</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>unset</em></span></p><p>Causes <code class="filename">sshfs</code> mounted filesystems for
          local applications to follow symlinks. By default it's false for
          symlinks under $HOME and true for any
          <code class="varname">LOCAL_APPS_EXTRAMOUNTS</code>.</p></dd><dt><span class="term"><code class="varname">LDM_SESSION</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Used to chose the default session on the server, for
          example:</p><pre class="screen">
LDM_SESSION="gnome-fallback"
 </pre><p>You can find the list of services that your server provides in
          <code class="filename">/usr/share/xsessions</code>.</p><p>If the user has selected a specific session though LDM or
          another DM in the past, that's stored in his
          <code class="filename">~/.dmrc</code>, and it overrides the default
          session.</p></dd><dt><span class="term"><code class="varname">LDM_FORCE_SESSION</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Same as <code class="varname">LDM_SESSION</code>, but it overrides any
          previously selected sessions by the user and it even hides the LDM
          session selection menu.</p></dd><dt><span class="term"><code class="varname">LDM_XSESSION</code></span></dt><dd><p>string, default <span class="emphasis"><em>Xsession</em></span></p><p>Allows you to specify custom script on the server for LDM to
          run, rather than the server's standard script for starting an X
          session (usually <span class="command"><strong>Xsession</strong></span>).</p></dd><dt><span class="term"><code class="varname">LDM_LIMIT_ONE_SESSION</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Only allow a given user to log into one thin-client at a
          time.</p></dd><dt><span class="term"><code class="varname">LDM_LIMIT_ONE_SESSION_PROMPT</code></span></dt><dd><p>boolean, default <span class="emphasis"><em>False</em></span></p><p>Prompt to kill processes of other logins when other logins are
          detected. Requires LDM_LIMIT_ONE_SESSION to be set.</p></dd><dt><span class="term"><code class="varname">LDM_THEME</code></span></dt><dd><p>string, default <span class="emphasis"><em>unset</em></span></p><p>Specify the name of the LDM theme. It can reference a
          directory in /usr/share/ldm/themes, or be specified as a full path
          to the theme dir (both relative to the chroot).</p><p>To use the theme in
          <code class="filename">/opt/ltsp/i386/usr/share/ldm/themes/MYTHEME</code>,
          you'd specify:</p><pre class="screen">
LDM_THEME=MYTHEME
                    </pre><p>In your <code class="filename">lts.conf</code> file.</p><p>Alternately, To use the theme in
          <code class="filename">/opt/ltsp/i386/etc/MYTHEME</code>, you'd
          specify:</p><pre class="screen">
LDM_THEME=/etc/MYTHEME
                    </pre><p>In your <code class="filename">lts.conf</code> file.</p></dd></dl></div></div><div class="sect1" title="Multiple server setup"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3055304"></a>Multiple server setup</h2></div></div></div><p>
                A multiple server setup is useful for larger thin client
                networks. Instead of using one big server, it makes it
                possible to use smaller servers, and dispatch users on them.
                You can adjust computing resources as the demand grows simply
                by adding a new server. To make sure that every server behaves
                the same from the users point of view, new services and
                configurations that are required will be discussed. In
                addition, some configurations specific to thin clients will be
                presented.
            </p></div></div><div class="chapter" title="Chapter 23. Infrastructure setup"><div class="titlepage"><div><div><h2 class="title"><a name="infrastructure"></a>Chapter 23. Infrastructure setup</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp3057032">Network topology</a></span></dt><dt><span class="sect1"><a href="#idp3058656">Common authentication</a></span></dt><dt><span class="sect1"><a href="#idp3062080">Shared home directories</a></span></dt><dt><span class="sect1"><a href="#idp3063160">Shared printers</a></span></dt><dt><span class="sect1"><a href="#idp3064320">Managing the SSH known hosts file</a></span></dt><dt><span class="sect1"><a href="#idp3067416">Setting Network Forwarding or Masquerading</a></span></dt></dl></div><div class="sect1" title="Network topology"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3057032"></a>Network topology</h2></div></div></div><p>
                The network topology is the same as a standalone server
                setup, except that there are more than one server on the thin
                client LAN.
            </p><p>
                You will need to select one server to behave as the primary
                server. This server will be used to run additional services,
                hold users files, and network boot thin clients.
            </p><p>
                Secondary servers will be used only to run desktop sessions.
                They are simpler, and will be configured to use the central
                services from the primary server.
            </p></div><div class="sect1" title="Common authentication"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3058656"></a>Common authentication</h2></div></div></div><p>
                A user should be able to start a session with the same login
                and password, no matter which server it connects to. For this
                purpose, a central authentication mechanism must be used.
                There are many possibilities offered. Here are the major
                technologies:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        LDAP authentication: On the master server, setup an
                        OpenLDAP server. Configure each servers to use this
                        LDAP server as the authentication base.
                    </p></li><li class="listitem"><p>
                        NIS authentication: On the master server, setup a
                        NIS server. Configure each server to use this NIS
                        server for the authentication.
                    </p></li><li class="listitem"><p>
                        Winbind authentication: Useful if you already have
                        an Active Directory server.
                    </p></li></ol></div><p>
                For detailed instructions, see their respective manuals.</p></div><div class="sect1" title="Shared home directories"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3062080"></a>Shared home directories</h2></div></div></div><p>
                Shared home directories are easy to setup using an NFS server
                on eithe the primary LTSP server, or even better, a standalone
                NFS server.  Other more modern, faster (and consequently more
                expensive) options include a SAN, and maybe even moving to a
                fibre-channel raid SAN.  Consult your distribution's
                documentation for details and suggestions for setting up an NFS
                server.
            </p></div><div class="sect1" title="Shared printers"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3063160"></a>Shared printers</h2></div></div></div><p>
                For printers to be accessible on each server, the cups
                server must be configured to share printers. Refer to the CUPS
                manual for your distribution for detailed setup instructions.
            </p><p>
                Note that an LTSP thin client acting as a print server
                resembles a JetDirect print server.
            </p></div><div class="sect1" title="Managing the SSH known hosts file"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3064320"></a>Managing the SSH known hosts file</h2></div></div></div><p>
                For security reasons, a thin client won't connect to an
                untrusted server. You must add the keys of secondary servers
                inside the client root on the primary server. To do this,
                first export the key file of the secondary server using LTSP's
                tools. As root, run:
            </p><pre class="screen">
ltsp-update-sshkeys --export ssh_known_hosts.myhostname
            </pre><p>
                Then, copy the file
                <code class="filename">ssh_known_hosts.myhostnam</code>
                to the primary server, in the directory
                <code class="filename">/etc/ltsp/</code>
                and run <span class="command"><strong>ltsp-update-sshkeys</strong></span> on the primary
                server. Then, thin clients will trust the freshly added
                server, and will be able to connect to it.
            </p><p>
                If a secondary server changes it's IP address, then this
                procedure must be repeated.
            </p></div><div class="sect1" title="Setting Network Forwarding or Masquerading"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3067416"></a>Setting Network Forwarding or Masquerading</h2></div></div></div><p>
                The purpose of IP Masquerading is to allow machines with
                private, non-routable IP addresses on your network to access
                the Internet through the machine doing the masquerading.
                Traffic from your private network destined for the Internet
                must be manipulated for replies to be routable back to the
                machine that made the request. To do this, the kernel must
                modify the <span class="emphasis"><em>source</em></span> IP address of each
                packet so that replies will be routed back to it, rather than
                to the private IP address that made the request, which is
                impossible over the Internet. Linux uses
                <span class="emphasis"><em>Connection Tracking</em></span>
                (conntrack) to keep track of which connections belong to which
                machines and reroute each return packet accordingly. Traffic
                leaving your private network is thus "masqueraded" as having
                originated from your gateway machine. This process is referred
                to in Microsoft documentation as Internet Connection Sharing.
            </p><p>
                IP Forwarding with IP Tables
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        to enable IPv4 packet forwarding by editing
                        /etc/sysctl.conf and uncomment the following
                        line:</p><pre class="screen">net.ipv4.ip_forward=1</pre></li><li class="listitem"><p>
                        If you wish to enable IPv6 forwarding also
                        uncomment:
                    </p><pre class="screen">net.ipv6.conf.default.forwarding=1</pre></li><li class="listitem"><p>
                        Next, execute the sysctl command to enable the new
                        settings in the configuration file:
                    </p><pre class="screen">sudo sysctl -p</pre></li><li class="listitem"><p>
                        IP Masquerading can now be accomplished with a
                        single iptables rule, which may differ slightly based
                        on your network configuration:
                    </p><pre class="screen">sudo iptables -t nat -A POSTROUTING -s 192.168.0.0/16 -o eth0 -j MASQUERADE</pre><p>
                        The above command assumes that your private address
                        space is 192.168.0.0/16 and that your Internet-facing
                        device is eth0. The syntax is broken down as follows:
                    </p></li></ol></div></div></div><div class="chapter" title="Chapter 24. Session dispatching"><div class="titlepage"><div><div><h2 class="title"><a name="session-dispatching"></a>Chapter 24. Session dispatching</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp3075136">Define the server list</a></span></dt><dt><span class="sect1"><a href="#idp3079064">Dispatching method</a></span></dt><dt><span class="sect1"><a href="#idp3082864">Network Swap</a></span></dt><dt><span class="sect1"><a href="#idp3088536">Managing DHCP</a></span></dt></dl></div><div class="sect1" title="Define the server list"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3075136"></a>Define the server list</h2></div></div></div><p>
                LDM is a login manager for thin clients. Users can select a
                server from the available ones in the host selection dialogue
                box.
            </p><p>
                The displayed server list is defined by the
                <code class="varname">LDM_SERVER</code>
                parameter. This parameter accepts a list of server IP address
                or host names, separated by space. If you use host names, then
                your DNS resolution must work on the thin client. If defined
                in the <code class="filename">lts.conf</code> file, the list order will
                be static, and the first server in the list will be selected
                by default.
            </p><p>
                You can also compute a new order for the server list, by
                creating the script
                <span class="command"><strong>/opt/ltsp/&lt;arch&gt;/usr/share/ltsp/get_hosts</strong></span>
                . The parameter
                <code class="varname">LDM_SERVER</code>
                overrides the
                script. In consequence, this parameter must not be defined if
                the <span class="command"><strong>get_hosts</strong></span> is going to be used. The
                <span class="command"><strong>get_hosts</strong></span>
                script writes on the standard output each server IP address or
                host names, in the chosen order.
            </p></div><div class="sect1" title="Dispatching method"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3079064"></a>Dispatching method</h2></div></div></div><p>
                You can change this behaviour by using a script to rearrange
                the list. The simplest way to do it is by randomizing the
                list. First, define a custom variable in the file
                <code class="filename">lts.conf</code>
                , for example <code class="varname">MY_SERVER_LIST</code>, that will
                contain the list of servers, the same way as
                <code class="varname">LDM_SERVER</code>
                Then, put the following script in
                <span class="command"><strong>/opt/ltsp/&lt;arch&gt;/usr/share/ltsp/get_hosts</strong></span>
            </p><pre class="screen">
#!/bin/bash
# Randomize the server list contained in MY_SERVER_LIST parameter
TMP_LIST=""
SHUFFLED_LIST=""

for i in $MY_SERVER_LIST; do
    rank=$RANDOM
    let "rank %= 100"
    TMP_LIST="$TMP_LIST\n${rank}_$i"
done

TMP_LIST=$(echo -e $TMP_LIST | sort)
for i in $TMP_LIST; do
    SHUFFLED_LIST="$SHUFFLED_LIST $(echo $i | cut -d_ -f2)"
done
echo $SHUFFLED_LIST
            </pre><p>
                More advanced load balancing algorithms can be written. For
                example, load balancing can be done by querying ldminfod for
                the server rating. By querying ldminfod, you can get the
                current rating state of the server. This rating goes from 0 to
                100, higher is better. Here is an example of such a query:
                </p><pre class="screen">nc localhost 9571 | grep rating | cut -d: -f2</pre><p>
            </p></div><div class="sect1" title="Network Swap"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3082864"></a>Network Swap</h2></div></div></div><p>
                Just like on a full fledged workstation, it helps to have
                swap defined for your thin client. "Swap" is an area of disk
                space set aside to allow you to transfer information out of
                ram, and temporarily store it on a hard drive until it's
                needed again. It makes the workstation look like it has more
                memory than it actually does. For instance, if your
                workstation has 64 Megabytes of ram and you configure 64
                Megabytes of swap, it's theoretically possible to load a 128
                Megabyte program.
            </p><p>
                We say, "theoretically", because in practice, you want to
                avoid swapping as much as possible. A hard drive is several
                orders of magnitude slower than ram, and, of course, on a thin
                client, you don't even have a hard drive! You have to first
                push the data through the network to the server's hard drive,
                thus making your swapping even slower. In practice, it's best
                to make sure you have enough ram in your thin client to handle
                all your average memory needs.
            </p><p>
                However, sometimes that's not possible. Sometimes, you're
                re-using old hardware, or you've simply got a program that
                isn't normally used, but does consume a lot of ram on the thin
                client when it does. Fortunately, LTSP supports swapping over
                the network via NBD, or Network Block Devices. We include a
                small shell script called nbdswapd, which is started via
                inetd. It handles creating the swap file, and setting up the
                swapping, and removing the swap file when it's no longer
                needed, after the terminal shuts down.
            </p><p>
                By default, swap files are 64 Megabytes in size. This was
                chosen to give your workstation a little extra ram, but not
                use up too much disk space. If you get some random odd
                behaviour, such as Firefox crashing when viewing web pages
                with a lot of large pictures, you may want to try increasing
                the size of the swap files. You can do so by creating a file
                in the directory <code class="filename">/etc/ltsp</code> on the LTSP
                server, called <code class="filename">nbdswapd.conf</code>. In it, you
                can set the SIZE variable to the number of Megabytes you wish
                the file to be sized to. For instance, to create 128 Megabyte
                files, you'll want: SIZE=128 in the <code class="filename">nbdswapd.conf</code> file.
            </p><p>
                Please note that this is a global setting for all swap files.
                If your server has 40 thin clients, each using 128 Megs of
                memory, you'll need 128 * 40 = 5120, or a little over 5
                Gigabytes of space in your <code class="filename">/tmp</code>
                directory, where the swap files are stored.
            </p></div><div class="sect1" title="Managing DHCP"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3088536"></a>Managing DHCP</h2></div></div></div><p>
                DHCP stands for Dynamic Host Configuration Protocol and is the
                very first thing your thin client uses to obtain an IP address
                from the network, in order to allow it to start booting. In
                LTSP, the dhcpd file is located in <code class="filename">/etc/ltsp</code>.
                Any changes you want to make to booting behaviour should be made there.
            </p><p>
                By default, LTSP ships a <code class="filename">dhcpd.conf</code> that
                serves thin clients in a dynamic range (i.e. it will hand out
                ip addresses to anyone who asks for them) from 192.168.0.20 to
                192.168.0.250. The default dhcpd.conf file looks like:
            </p><pre class="screen">
#
# Default LTSP dhcpd.conf config file.
#

authoritative;

subnet 192.168.0.0 netmask 255.255.255.0 {
    range 192.168.0.20 192.168.0.250;
    option domain-name "example.com";
    option domain-name-servers 192.168.0.1;
    option broadcast-address 192.168.0.255;
    option routers 192.168.0.1;
#    next-server 192.168.0.1;
#    get-lease-hostnames true;
    option subnet-mask 255.255.255.0;
    option root-path "/opt/ltsp/i386";
    if substring( option vendor-class-identifier, 0, 9 ) = "PXEClient" {
        filename "/ltsp/i386/pxelinux.0";
    } else {
        filename "/ltsp/i386/nbi.img";
    }
}
            </pre><p>
                This <code class="filename">dhcpd.conf</code> should handle most
                situations.
            </p><p>
                By default, LTSP will detect an unused network interface and
                configure it to be 192.168.0.254. LTSP's recommended single
                server installation is to use a separate network interface for
                the thin clients. If, however, you're not using two network
                interfaces, or you already have an interface in the 192.168.0
                range, then you might have to configure the thin client
                interface differently, which means you may have to adjust the
                <code class="filename">dhcpd.conf</code> accordingly.
            </p><p>
                If the network interface that you're going to connect the thin
                clients to has, say, a TCP/IP address of 10.0.20.254, you'll
                want to replace every occurrence of 192.168.0 with 10.0.20 in
                the <code class="filename">dhcpd.conf</code> file.
            </p><p>
                Always remember, you'll need to re-start the dhcp server if
                you make any changes. You can do this by issuing the command:
            </p><pre class="screen">sudo invoke-rc.d dhcp3-server restart</pre><p>(at the command prompt.)</p></div></div><div class="chapter" title="Chapter 25. Adding static entries to the dhcpd.conf"><div class="titlepage"><div><div><h2 class="title"><a name="static-entries-dhcp"></a>Chapter 25. Adding static entries to the dhcpd.conf</h2></div></div></div><p>
            Sometimes, you may need to have a certain terminal boot with a
            guaranteed fixed TCP/IP address every time. Say, if you're
            connecting a printer to the terminal, and need to make sure the
            print server can find it at a fixed address. To create a fixed
            address, use a low number in the range of 2-19, or otherwise, if
            you change the range statement in the <code class="filename">dhcpd.conf</code>.
        </p><p>
            To create a static entry, simply add the following after the
            "option root-path" line:
        </p><pre class="screen">
host hostname {
    hardware ethernet MA:CA:DD:RE:SS:00;
    fixed-address 192.168.0.2;
}
            </pre><p>
                Substitude the MAC
            address for the mac address of the thin client you wish to fix the
            address of. The fixed-address will be the TCP/IP address you want,
            and "hostname" is the name you wish to give the host. This kind of
            setup is relatively complex and the admin should have a full
            understanding of how DHCP works before attempting such a setup.
            For more information, check the Internet.
        </p></div><div class="chapter" title="Chapter 26. DHCP failover load balancing"><div class="titlepage"><div><div><h2 class="title"><a name="dhcp-loadbalance"></a>Chapter 26. DHCP failover load balancing</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp3100080"></a></span></dt><dd><dl><dt><span class="sect2"><a href="#idp3100640">Lockdown with Sabayon (user profile manager) and
                    Pessulus (lockdown editor)
                </a></span></dt></dl></dd><dt><span class="sect1"><a href="#idp3105288">Replication of desktop profiles</a></span></dt></dl></div><p>
            Another common method of load balancing is to use DHCP
            load balancing. There's an excellent writeup on the topic at:
            <a class="ulink" href="https://wiki.edubuntu.org/EdubuntuDHCPload-balancingFailover" target="_top">
                https://wiki.edubuntu.org/EdubuntuDHCPload-balancingFailover
            </a>
        </p><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3100080"></a></h2></div></div></div><div class="sect2" title="Lockdown with Sabayon (user profile manager) and Pessulus (lockdown editor)"><div class="titlepage"><div><div><h3 class="title"><a name="idp3100640"></a>Lockdown with Sabayon (user profile manager) and
                    Pessulus (lockdown editor)
                </h3></div></div></div><p>
                    A common requirement in both schools and businesses is
                    having the ability to lock down the desktop and provide
                    certain default configurations.
                </p><p>
                    In LTSP, the applications you'll want to use are Sabayon
                    and Pessulus. You'll want to add them from the package
                    manager.
                </p><p>
                    The Sabayon user profile editor looks like a window that
                    contains a smaller sized picture of your desktop. Within
                    this window, you can create a default layout: add icons to
                    panels and the desktop, lock down the panels so they can't
                    be modified, remove access to the command line, etc.
                </p><p>
                    Once you're done, you can save your profile. You have
                    the option of applying your profile to either individual
                    users, or all users on the system. Please consult the
                    manual included with Sabayon for all the details.
                </p><p>
                    More information is available here:</p><p>
                    <a class="ulink" href="http://live.gnome.org/PythonSabayon" target="_top">
                        http://live.gnome.org/PythonSabayon
                    </a>
                </p><p>
                    <a class="ulink" href="http://www.gnome.org/~seth/blog/sabayon" target="_top">
                        http://www.gnome.org/~seth/blog/sabayon
                    </a>
                </p><p>
                    http://www.gnome.org/projects/sabayon/</p></div></div><div class="sect1" title="Replication of desktop profiles"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3105288"></a>Replication of desktop profiles</h2></div></div></div><p>
                If you customize user's desktop, then custom desktop profiles
                should be copied to every server. Gnome desktop profiles
                created with Sabayon are located in
                <code class="filename">/etc/desktop-profiles</code>
            </p></div></div><div class="chapter" title="Chapter 27. Managing the thin client"><div class="titlepage"><div><div><h2 class="title"><a name="managing-clients"></a>Chapter 27. Managing the thin client</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp3107856">Lockdown Editor</a></span></dt></dl></div><p>
            Previously, there was a program called TCM or thin client
            manager, which was responsible for checking what was happening on
            the various thin terminals, messaging between them, locking, or
            generally offering support from a master terminal. This has now
            been replaced by the use of Italc, which must be separately
            installed depending on your distribution.
        </p><div class="sect1" title="Lockdown Editor"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3107856"></a>Lockdown Editor</h2></div></div></div><p>
                By choosing a single user and right clicking on that users
                name, you will open up the context menu. From here you can
                choose "Lockdown", which will allow you to set options to
                restrict a particular user. Clicking this menu item will
                invoke the "Pessulus" program, which is the Gnome lockdown
                editor. Ticking and unticking options in Pessulus will enable
                and disable certain functions for that particular user. There
                is a padlock next to each option in Pessulus. Ticking this
                will make the option unchangeable by the user. This is called
                a mandatory setting. For further help with Pessulus, please
                refer to the Pessulus documentation.
            </p></div></div><div class="chapter" title="Chapter 28. Updating your LTSP chroot"><div class="titlepage"><div><div><h2 class="title"><a name="updating-chroot"></a>Chapter 28. Updating your LTSP chroot</h2></div></div></div><p>
            At some point in the future, updates will become available for
            your LTSP server. You must remember that although you may have
            applied all the updates to the server itself, as in the
            instructions....HERE it is likely that the LTSP chroot will also
            need updating. To do this you must open up a terminal and use the
            following commands.
        </p><p>
            First make sure the Client environment has the same Package
            lists as the Server, to achieve that, you will copy the
            /etc/apt/sources.list (on Debian and Ubuntu) or the
            /etc/yum.repos.d/fedora.repo  file from the Server to the Client
            environment.
        </p><p>
            Now issue the command below.</p><pre class="screen">sudo chroot /opt/ltsp/&lt;arch&gt;</pre><p>(replace &lt;arch&gt; with the architecture
            you are working with.)
        </p><p>
            This will change your root directory to be the LTSP clients root
            directory. In essence, anything you now do inside here, will be
            applied to the LTSP clients root. This is a separate small set of
            files that are used to boot the clients into a usable, and enable
            them to contact the LTSP server. Once inside this shell, we must
            type the following command to obtain the latest list of packages
            from the apt/yum servers.
        </p><pre class="screen">apt-get get update</pre><p>
            on Debian and Ubuntu
        </p><p>
            You need to mount <code class="filename">/proc</code> in the chroot before beginning, as some of
            the packages you install may need resources in <code class="filename">/proc</code> to install correctly.
        </p><pre class="screen">mount -t proc proc /proc</pre><p>
            To be sure no deamons are started do the following:</p><pre class="screen">export LTSP_HANDLE_DAEMONS=false</pre><p>
            Once this has completed you will have to upgrade the software in
            the chroot by running the following command:
        </p><pre class="screen">apt-get upgrade</pre><p>(on Debian and Ubuntu)</p><p>
            or
        </p><pre class="screen">yum update</pre><p>(on Fedora)</p><p>
            Just in case <code class="filename">/proc</code> is still mounted when you exit the chroot,
            unmount it first by doing:</p><pre class="screen">umount /proc</pre><p>
            Once you're done, you must leave the chroot by either typing
            <span class="emphasis"><em>exit</em></span>
            or by using the key combination Ctrl+D. This will return you to
            the root of the server.
        </p><p>
            If your kernel has been upgraded you must run the LTSP kernel
            upgrade script, to ensure that your LTSP chroot uses the latest
            version. This is performed by running the command below:
        </p><pre class="screen">ltsp-update-kernels</pre><p>
            All of your clients will now use the latest kernel upon their
            next reboot.
        </p><p>
            Finally, you must remember to rebuild the NBD boot image from
            your chroot with the following command:
        </p><pre class="screen">ltsp-update-image</pre><p>(add architecture using -arch= addition)</p><p>
            Be advised that this may take a few minutes, depending on the
            speed of your server.
        </p></div><div class="chapter" title="Chapter 29. Changing the IP of your LTSP server"><div class="titlepage"><div><div><h2 class="title"><a name="changing-server-ip"></a>Chapter 29. Changing the IP of your LTSP server</h2></div></div></div><p>
            At some point in time, it may become necessary to change the IP
            address of your LTSP server. Normally this does not present an
            issue, but LTSP servers and clients communicate over and encrypted
            channel and require all SSL certificates to be updated. Without
            this update, <span class="emphasis"><em>no LTSP clients will be able to log in</em></span>.
            This is done by simply opening a terminal and running the following command.
        </p><pre class="screen">
sudo ltsp-update-sshkeys
sudo ltsp-update-image
        </pre></div><div class="chapter" title="Chapter 30. Appendix I"><div class="titlepage"><div><div><h2 class="title"><a name="appendix"></a>Chapter 30. Appendix I</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="#idp3123312">Using NFS instead of NBD</a></span></dt><dt><span class="sect1"><a href="#idp3131920">Enabling dual monitors</a></span></dt></dl></div><p>
            Here you can find some solutions to common questions and
            problems.
        </p><div class="sect1" title="Using NFS instead of NBD"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3123312"></a>Using NFS instead of NBD</h2></div></div></div><p>
                Using NBD instead of NFS has several advantages:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        Using a squashfs image we can now merge that
                        together in a unionfs to get writeable access which is
                        a lot faster during bootup.
                    </p></li><li class="listitem"><p>
                        A squashed root filesystem uses less network
                        bandwidth.
                    </p></li><li class="listitem"><p>
                        Many users and administrators have asked us to
                        eliminate NFS, for reasons of site policy. Since the
                        squashed image is now served out by nbd-server, which
                        is an entirely userspace program, and is started as
                        the user nobody, this should help to eliminate
                        concerns over NFS shares.
                    </p></li></ol></div><p>
                However, some people still want to use NFS. Fortunately,
                it's easy to switch back to NFS, if it's so desired:
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
                        On the server, use the chroot command to maintain
                        the LTSP chroot:</p><pre class="screen">sudo chroot /opt/ltsp/&lt;arch&gt;</pre></li><li class="listitem"><p>
                        Now edit /etc/default/ltsp-client-setup and change
                        the value of the root_write_method variable to use
                        bind mounts instead of unionfs, it should look like
                        this afterwards:
                    </p><pre class="screen">root_write_method="bind_mounts"</pre></li><li class="listitem"><p>
                        Next, create the file
                        <code class="filename">/etc/initramfs-tools/conf.d/ltsp</code> and add the following
                        line (set the value of the BOOT variable to nfs):
                    </p><pre class="screen">BOOT=nfs</pre></li><li class="listitem"><p>
                        Regenerate the initramfs: </p><pre class="screen">update-initramfs -u</pre></li><li class="listitem"><p>
                        Hit CTRL-D to exit the chroot now. Make sure LTSP
                        uses the new initramfs to boot:
                    </p><pre class="screen">sudo ltsp-update-kernels</pre></li></ol></div></div><div class="sect1" title="Enabling dual monitors"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="idp3131920"></a>Enabling dual monitors</h2></div></div></div><p>
                First, I am going to start with a couple assumptions:</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
                        I will assume that you are operating thin clients
                          with an NBD file system in this write-up.
                    </p></li><li class="listitem"><p>
                        I will assume that you are running Ubuntu 8.04.1</p></li><li class="listitem"><p>
                        I will assume that you are running LTSP 5</p></li><li class="listitem"><p>
                        I will assume that you are replacing a running
                        image that has been properly tested, and is working.
                    </p></li></ul></div><p>
                Create a
                new image to ensure your configuration is congruent with my
                successfully tested configuration.
            </p><pre class="screen">
sudo ltsp-build-client --copy-sourceslist --arch i386
            </pre><p>
                (note the --arch i386 command is required for my system
                because it's running an amd64 kernel. It may not be required
                for individuals running a 32-bit kernel)
            </p><p>
                Download the pertinent VIA unichrome driver for your chipset
                from this web site: <a class="ulink" href="http://linux.via.com.tw/support/downloadFiles.action" target="_top">
                    http://linux.via.com.tw/support/downloadFiles.action
                </a>
                Be sure to select the proper OS as well. The installation
                script is set up specifically for the directory structure of
                each OS, and will error out if the wrong OS release is
                installed. Next we need to move the downloaded file to the
                image directory
            </p><pre class="screen">
cp /home/&lt;username/Desktop/chrome9.83-242-sl10.1.tar.gz /opt/ltsp/i386
            </pre><p>
                After that, we need to chroot to the same image directory.</p><pre class="screen">
sudo chroot /opt/ltsp/i386/
            </pre><p>
                Unpack the driver in the root directory </p><pre class="screen">
tar -zxvf chrome9.83-242-sl10.1.tar.gz
            </pre><p>
                After unpacking, enter the directory:</p><pre class="screen">
cd chrome9.83-242-sl10.1/
            </pre><p>
                Run the file contained inside to start the driver installation
            </p><pre class="screen">
./vinstall ..................done! Original X config file
was saved as /etc/X11/xorg.conf.viabak
            </pre><p>(The following error: "VIAERROR:The /etc/X11/xorg.conf is
                missing!" Can be ignored. We will be replacing the xorg.conf
                anyway, and the drivers are still installed properly.)
            </p><p>
                Next we need to put a proper xorg.conf in to the proper
                directory.
            </p><pre class="screen">
gedit /etc/X11/xorg.conf
            </pre><p>
                Now paste the following in to the empty file:
            </p><pre class="screen">
Section "Module"
    Load "extmod"
    Load "dbe"
    Load "dri"
    Load "glx"
    Load "freetype"
    Load "type1"
EndSection

Section "Files"
    RgbPath "/usr/X11R6/lib/X11/rgb"
    FontPath "/usr/X11R6/lib/X11/fonts/misc/"
    FontPath "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
    FontPath "/usr/X11R6/lib/X11/fonts/75dpi/"
    FontPath "/usr/X11R6/lib/X11/fonts/Type1"
    FontPath "/usr/X11R6/lib/X11/fonts/TTF"
EndSection

Section "ServerFlags"
    Option "Dont Zoom"
    Option "AllowMouseOpenFail" "Yes"
    Option "BlankTime" "20"
    Option "StandbyTime" "0"
    Option "SuspendTime" "0"
    Option "OffTime" "0"
    Option "Xinerama" "on"
EndSection

Section "InputDevice"
    Identifier "Keyboard1"
    Driver "Keyboard"
    Driver "keyboard"
    Option "AutoRepeat" "500 30"
    Option "XkbRules" "xfree86"
    Option "XkbModel" "pc105"
    Option "XkbLayout" "en_US,en_US"
    Option "XkbOptions" "grp:alt_shift_toggle,grp_led:scroll" EndSection
EndSection

Section "InputDevice"
    Identifier "USBMouse"
    Driver "mouse"
    Option "Protocol" "IMPS/2"
    Option "Device" "/dev/input/mice"
    Option "ZAxisMapping" "4 5"
    Option "Buttons" "5"
EndSection

Section "InputDevice"
    Identifier "Mouse1"
    Driver "mouse"
    Option "Protocol" "Auto"
    Option "Device" "/dev/psaux"
    Option "ZAxisMapping" "4 5"
    Option "Buttons" "5"
EndSection

Section "Monitor"
    Identifier "Monitor0"
    HorizSync 31.5-48.5
    VertRefresh 60
    Option "DPMS"
EndSection

Section "Device"
    Identifier "CN700"
    Driver "via"
    VideoRam 16384
    Screen 0
    Option "NoDDCValue" "1"
    Option "Simultaneous"
    Option "DPMS" "on"
    BusID "PCI:1:0:0"
EndSection

Section "Screen"
    Identifier "Screen0DVI"
    Device "CN700DVI"
    Monitor "Monitor0DVI"
    DefaultDepth 24
    Subsection "Display"
        Depth 8
        Modes "1280x1024"
        ViewPort 0 0
    EndSubsection
    Subsection "Display"
        Depth 16
        Modes "1280x1024"
        ViewPort 0 0
    EndSubsection
    Subsection "Display"
        Depth 24
        Modes "1280x1024"
        ViewPort 0 0
    EndSubsection
EndSection

Section "Monitor"
    Identifier "Monitor0"
    HorizSync 31.5-48.5
    VertRefresh 60
    Option "DPMS"
EndSection

Section "Device"
    Identifier "CN700DVI"
    Driver "via"
    VideoRam 16384
    Screen 1
    Option "NoDDCValue" "1"
    Option "Simultaneous"
    Option "DPMS" "on"
    BusID "PCI:1:0:0"
EndSection

Section "Screen"
    Identifier "Screen0"
    Device "CN700"
    Monitor "Monitor0"
    DefaultDepth 24
    Subsection "Display"
        Depth 8
        Modes "1280x1024"
        ViewPort 0 0
    EndSubsection
    Subsection "Display"
        Depth 16
        Modes "1280x1024"
        ViewPort 0 0
    EndSubsection
    Subsection "Display"
        Depth 24
        Modes "1280x1024"
        ViewPort 0 0
    EndSubsection
EndSection

Section "ServerLayout"
    Identifier "Simple Layout"
    Screen "Screen0" 0 0
    Screen 1 "Screen0DVI" LeftOf "Screen0"
    InputDevice "Mouse1" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
    InputDevice "USBMouse" "AlwaysCore"
EndSection
            </pre><p>
                <span class="emphasis"><em>IMPORTANT NOTE</em></span> IN THE ABOVE SECTION PASTED INTO THE XORG.CONF, NOTICE
                THAT THERE ARE RESOLUTIONS SPECIFIED PER MONITOR. PLEASE
                ENSURE THAT YOU HAVE THE PROPER RESOLUTIONS FOR YOU YOUR
                MONITOR ENTERED ON THOSE AREAS. Be sure to save the file as
                xorg.conf and exit out of your chroot'd image. &lt;CTRL+D or
                "exit"&gt; next we need to put in an addendum in the
                lts.conf
            </p><pre class="screen">
gedit /var/lib/tfpboot/ltsp/i386/lts.conf
            </pre><p>
                Feel
                free to comment out anything that you need to in the lts.conf.
                I will include my full lts.conf as an example:
            </p><pre class="screen">
[DEFAULT]
    #X_COLOR_DEPTH = "16"
    #X_MODE_0 = "1680x1050"
    #X_VERTREFRESH = "43-61"
    #X_HORZSYNC = "28-85"
    #X_OPTION_01 = "\"ForcePanel\" \"True\""
    #X_OPTION_01 = "\"NoPanel\" \"true\""
    #SCREEN_02 = shell
    #SCREEN_07 = ldm
    X_CONF = /etc/X11/xorg.conf
            </pre><p>
                Feel free to copy-paste this in it's
                entirety if you want, but you will only need the last line.
                After you add the X_CONF line, save &amp; exit. Now we need to
                make the changes that we have made take effect in the image
            </p><pre class="screen">
# sudo ltsp-update-image --arch i386
            </pre><p>(again, the --arch i386
                will not be required for most, but I am putting it in just in
                case a user has a x64 installation on their server.) That
                should do it! Boot up the client and you should be good to go.
            </p></div></div></div></body></html>