/usr/share/debian-reference/ch03.it.html is in debian-reference-it 2.72.
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 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 | <?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Capitolo 3. Inizializzazione del sistema</title>
<link rel="stylesheet" type="text/css" href="debian-reference.css"/>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"/>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<link rel="home" href="index.it.html" title="Debian Reference"/>
<link rel="up" href="index.it.html" title="Debian Reference"/>
<link rel="prev" href="ch02.it.html" title="Capitolo 2. Gestione dei pacchetti in Debian"/>
<link rel="next" href="ch04.it.html" title="Capitolo 4. Autenticazione"/>
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">Capitolo 3. Inizializzazione del sistema</th>
</tr>
<tr>
<td align="left"><a accesskey="p" href="ch02.it.html"><img src="images/prev.png" alt="Indietro"/></a> </td>
<th width="60%" align="center"> </th>
<td align="right"> <a accesskey="n" href="ch04.it.html"><img src="images/next.png" alt="Avanti"/></a></td>
</tr>
</table>
<hr/>
</div>
<div class="chapter">
<div class="titlepage">
<div>
<div>
<h1 class="title"><a id="_the_system_initialization"/>Capitolo 3. Inizializzazione del sistema</h1>
</div>
</div>
</div>
<div class="toc">
<p>
<strong>Indice</strong>
</p>
<dl class="toc">
<dt>
<span class="section">
<a href="ch03.it.html#_an_overview_of_the_boot_strap_process">3.1. Panoramica del processo di avvio</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="ch03.it.html#_stage_1_the_bios">3.1.1. Stadio 1: il BIOS</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_stage_2_the_boot_loader">3.1.2. Stadio 2: il bootloader</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_stage_3_the_mini_debian_system">3.1.3. Stadio 3: il mini-sistema Debian</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_stage_4_the_normal_debian_system">3.1.4. Stadio 4: il normale sistema Debian</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="ch03.it.html#_systemd_init">3.2. Systemd init</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="ch03.it.html#_the_hostname">3.2.1. Il nome host</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_the_filesystem">3.2.2. Il filesystem</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_network_interface_initialization">3.2.3. Inizializzazione delle interfacce di rete</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_the_kernel_message">3.2.4. I messaggi del kernel</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_the_system_message">3.2.5. I messaggi di sistema</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_system_management_under_systemd">3.2.6. System management under systemd</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ch03.it.html#_customizing_systemd">3.2.7. Customizing systemd</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="ch03.it.html#_the_udev_system">3.3. Il sistema udev</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="ch03.it.html#_the_kernel_module_initialization">3.3.1. L'inizializzazione dei moduli del kernel</a>
</span>
</dt>
</dl>
</dd>
</dl>
</div>
<p>È bene che l'amministratore di sistema conosca almeno a grandi linee come
viene avviato e configurato il sistema Debian. Anche se i dettagli precisi
sono nei file sorgenti dei pacchetti installati e nella loro documentazione,
essi sono un po' troppo per la maggior parte degli utenti.</p>
<p>Ho cercato di fornire una veloce panoramica dei punti chiave del sistema
Debian e della loro configurazione, come punto di riferimento per l'utente,
in base alle conoscenze attuali e passate mie e di altri. Dato che il
sistema Debian è in costante evoluzione, la situazione potrebbe essere
cambiata. Prima di fare qualsiasi modifica al sistema, si dovrebbe far
riferimento alla documentazione più recente per ciascun pacchetto.</p>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p><span class="citerefentry"><span class="refentrytitle">bootup</span>(7)</span>
describes the system bootup process based on <code class="literal">systemd</code>
. (Recent Debian)</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p><span class="citerefentry"><span class="refentrytitle">boot</span>(7)</span>
describes the system bootup process based on UNIX System V Release 4. (Older
Debian)</p>
</td>
</tr>
</table>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title"><a id="_an_overview_of_the_boot_strap_process"/>3.1. Panoramica del processo di avvio</h2>
</div>
</div>
</div>
<p>Il sistema del computer passa attraverso varie fasi del <a class="ulink" href="http://it.wikipedia.org/wiki/Boot">processo di avvio</a>, dall'accensione a
quando offre all'utente il sistema operativo (SO) pienamente funzionante.</p>
<p>Per semplicità la spiegazione è limitata alla piattaforma PC tipica con
l'installazione standard.</p>
<p>Il normale processo di avvio è come un razzo a quattro stadi. Ogni stadio
del razzo passa il controllo del sistema allo stadio successivo.</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
<a class="xref" href="ch03.it.html#_stage_1_the_bios" title="3.1.1. Stadio 1: il BIOS">Sezione 3.1.1, «Stadio 1: il BIOS»</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="ch03.it.html#_stage_2_the_boot_loader" title="3.1.2. Stadio 2: il bootloader">Sezione 3.1.2, «Stadio 2: il bootloader»</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="ch03.it.html#_stage_3_the_mini_debian_system" title="3.1.3. Stadio 3: il mini-sistema Debian">Sezione 3.1.3, «Stadio 3: il mini-sistema Debian»</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="ch03.it.html#_stage_4_the_normal_debian_system" title="3.1.4. Stadio 4: il normale sistema Debian">Sezione 3.1.4, «Stadio 4: il normale sistema Debian»</a>
</p>
</li>
</ul>
</div>
<p>Naturalmente questo può essere configurato in modo diverso. Per esempio, se
è stato compilato un kernel personalizzato, si potrebbe saltare la fase con
il mini-sistema Debian. Non dare per scontato che quanto detto valga per il
proprio sistema fino a che non si abbia controllato direttamente.</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Nota]" src="images/note.png"/>
</td>
<th align="left">Nota</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Per piattaforme PC non sorpassate, come il sistema SUN o Macintosh, il BIOS
nella ROM e la partizione sul disco possono essere alquanto differenti
(<a class="xref" href="ch09.it.html#_disk_partition_configuration" title="9.5.2. Configurazione del partizionamento dei dischi">Sezione 9.5.2, «Configurazione del partizionamento dei dischi»</a>). In questi casi, cercare
la documentazione piattaforma specifica altrove.</p>
</td>
</tr>
</table>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_stage_1_the_bios"/>3.1.1. Stadio 1: il BIOS</h3>
</div>
</div>
</div>
<p>Il <a class="ulink" href="http://it.wikipedia.org/wiki/Bios">BIOS</a> è il primo stadio del processo di avvio
che viene avviato dall'accensione. Il <a class="ulink" href="http://it.wikipedia.org/wiki/Bios">BIOS</a>, che
risiede nella <a class="ulink" href="http://it.wikipedia.org/wiki/Read-Only_Memory">ROM (read only memory,
memoria in sola lettura)</a> è eseguito da un particolare indirizzo di
memoria al quale è inizializzato, dall'accensione, il contatore di programma
della CPU.</p>
<p>Il BIOS effettua l'inizializzazione base dell'hardware (<a class="ulink" href="http://it.wikipedia.org/wiki/Power-on_self-test">POST (power on self test, auto-test di
accensione)</a> e passa il controllo del sistema allo stadio successivo
fornito dall'utente. Il BIOS è di solito fornito con l'hardware.</p>
<p>La schermata di avvio del BIOS indica solitamente quale tasto o tasti
premere per entrare nella schermata di impostazioni del BIOS, per
configurarne il comportamento. Tasti comunemente usati sono F1, F2, F10,
Esc, Ins e Canc. Se la schermata di avvio del BIOS è nascosta da una bella
schermata grafica, si può premere dei tasti, come Esc, per
disabilitarla. Quali tasti vadano premuti dipende fortemente dall'hardware.</p>
<p>Dalla schermata di impostazioni del BIOS si può scegliere la posizione
hardware e la priorità del codice avviato dal BIOS. Tipicamente vengono
caricati in memoria i primi pochi settori del primo dispositivo selezionato
trovato (disco fisso, dischetto floppy, CD-ROM, ...) e viene eseguito questo
codice iniziale che può essere una qualsiasi tra le cose seguenti.</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
Il codice del bootloader
</p>
</li>
<li class="listitem">
<p>
Il codice del kernel di SO di passaggio come <a class="ulink" href="http://www.freedos.org/">FreeDOS</a>
</p>
</li>
<li class="listitem">
<p>
Il codice del kernel del sistema operativo finale, se può essere contenuto
in questo piccolo spazio
</p>
</li>
</ul>
</div>
<p>Tipicamente il sistema viene avviato dalla partizione specificata del disco
fisso primario. I primi 2 settori del disco fisso nei PC vecchi contengono
il<a class="ulink" href="http://it.wikipedia.org/wiki/Master_boot_record">master boot record (MBR)</a>. Le
informazioni sulle partizioni del disco, inclusa la selezione per l'avvio
sono memorizzate alla fine di questo MBR. Il primo codice boot loader
eseguito dal BIOS occupa la parte restante di questo MBR.</p>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_stage_2_the_boot_loader"/>3.1.2. Stadio 2: il bootloader</h3>
</div>
</div>
</div>
<p>Il <a class="ulink" href="http://it.wikipedia.org/wiki/Boot_loader">bootloader</a> è il secondo stadio del
processo di avvio che è iniziato dal BIOS. Carica l'immagine kernel del
sistema e l'immagine <a class="ulink" href="http://it.wikipedia.org/wiki/Initrd">initrd</a> in memoria e passa
il controllo ad essi. L'immagine initrd è l'immagine del file system radice
ed il suo supporto dipende dal bootloader usato.</p>
<p>Il sistema Debian normalmente usa il kernel Linux come kernel predefinito
del sistema. L'immagine initrd dell'attuale kernel Linux 2.6/3.x è
tecnicamente l'immagine initramfs (initial RAM filesystem). Questa è un
archivio cpio compresso con gzip dei file nel filesystem root.</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Avvertimento]" src="images/warning.png"/>
</td>
<th align="left">Avvertimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Quanto sopra non è più vero con il nuovo initramfs multi-segmento. Vedere il
<a class="ulink" href="https://bugs.debian.org/790100">bug n. 790100</a>.</p>
</td>
</tr>
</table>
</div>
<p>L'installazione predefinita del sistema Debian posiziona, per la piattaforma
PC, il codice di primo stadio del bootloader GRUB nell'<a class="ulink" href="http://it.wikipedia.org/wiki/Master_boot_record">MBR</a>. Sono disponibili molti bootloader e opzioni di
configurazione.</p>
<div class="table">
<a id="listofbootloaders"/>
<p class="title">
<strong>Tabella 3.1. Elenco di bootloader</strong>
</p>
<div class="table-contents">
<table class="table" summary="Elenco di bootloader" border="1">
<colgroup>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
</colgroup>
<thead>
<tr>
<th style="text-align: left">
pacchetto
</th>
<th style="text-align: left">
popcon
</th>
<th style="text-align: left">
dimensione
</th>
<th style="text-align: left">
initrd
</th>
<th style="text-align: left">
bootloader
</th>
<th style="text-align: left">
descrizione
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/grub-legacy"> grub-legacy
</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=grub-legacy">V:0, I:2</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/g/grub-legacy.html">710</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://en.wikipedia.org/wiki/GRUB">GRUB Legacy</a>
</td>
<td style="text-align: left">
Intelligente abbastanza da capire partizioni su disco e filesystem come
vfat, ext3, ...
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/grub-pc"> grub-pc </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=grub-pc">V:29, I:849</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/g/grub-pc.html">584</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://en.wikipedia.org/wiki/GRUB">GRUB 2</a>
</td>
<td style="text-align: left">
Intelligente abbastanza da capire partizioni su disco e filesystem come
vfat, ext4, …. (predefinito)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/grub-rescue-pc"> grub-rescue-pc
</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=grub-rescue-pc">V:0, I:1</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/g/grub-rescue-pc.html">6294</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://en.wikipedia.org/wiki/GRUB">GRUB 2</a>
</td>
<td style="text-align: left">
È l'immagine di ripristino avviabile di GRUB 2 (CD e floppy) (versione
PC/BIOS)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/lilo"> lilo </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=lilo">V:0, I:3</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/l/lilo.html">693</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://it.wikipedia.org/wiki/LILO">Lilo</a>
</td>
<td style="text-align: left">
Si basa sulla posizione dei settori dei dati sul disco fisso. (Vecchio)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/syslinux"> syslinux </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=syslinux">V:5, I:59</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/syslinux.html">299</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://en.wikipedia.org/wiki/SYSLINUX">Isolinux</a>
</td>
<td style="text-align: left">
Capisce il filesystem ISO 9660. Usato dal CD di avvio.
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/syslinux"> syslinux </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=syslinux">V:5, I:59</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/syslinux.html">299</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://en.wikipedia.org/wiki/SYSLINUX">Syslinux</a>
</td>
<td style="text-align: left">
Capisce il <a class="ulink" href="http://it.wikipedia.org/wiki/File_Allocation_Table">filesystem MSDOS
(FAT)</a>. Usato dai dischetti floppy di avvio.
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/loadlin"> loadlin </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=loadlin">V:0, I:1</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/l/loadlin.html">84</a>
</td>
<td style="text-align: left">
Supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://en.wikipedia.org/wiki/Loadlin">Loadlin</a>
</td>
<td style="text-align: left">
Il nuovo sistema viene avviato dal sistema FreeDOS/MSDOS.
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/mbr"> mbr </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=mbr">V:0, I:10</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/m/mbr.html">50</a>
</td>
<td style="text-align: left">
Non supportato
</td>
<td style="text-align: left">
<a class="ulink" href="http://www.chiark.greenend.org.uk/~neilt/">MBR di Neil Turton</a>
</td>
<td style="text-align: left">
Software libero che sostituisce <a class="ulink" href="http://it.wikipedia.org/wiki/Master_boot_record">MBR</a>
MSDOS. Capisce solo le partizioni su disco.
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Avvertimento]" src="images/warning.png"/>
</td>
<th align="left">Avvertimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Do not play with boot loaders without having bootable rescue media (USB
memory stick, CD or floppy) created from images in the
<code class="literal">grub-rescue-pc</code> package. It makes you boot your system
even without functioning bootloader on the hard disk.</p>
</td>
</tr>
</table>
</div>
<p>Per GRUB Legacy, il file di configurazione del menu è
"<code class="literal">/boot/grub/menu.lst</code>". Contiene, per esempio, delle voci
come quella seguente.</p>
<pre class="screen">title Debian GNU/Linux
root (hd0,2)
kernel /vmlinuz root=/dev/hda3 ro
initrd /initrd.img</pre>
<p>Per GRUB 2, il file di configurazione del menu è
"<code class="literal">/boot/grub/grub.cfg</code>". Viene generato automaticamente da
"<code class="literal">/usr/sbin/update-grub</code>" usando modelli da
"<code class="literal">/etc/grub.d/*</code>" e impostazioni da
"<code class="literal">/etc/default/grub</code>". Contiene, per esempio, delle voci
come quella seguente.</p>
<pre class="screen">menuentry "Debian GNU/Linux" {
set root=(hd0,3)
linux /vmlinuz root=/dev/hda3
initrd /initrd.img
}</pre>
<p>Negli esempi precedenti i parametri di GRUB hanno i seguenti significati.</p>
<div class="table">
<a id="themeaningofgrubparameters"/>
<p class="title">
<strong>Tabella 3.2. Significato dei parametri di GRUB</strong>
</p>
<div class="table-contents">
<table class="table" summary="Significato dei parametri di GRUB" border="1">
<colgroup>
<col style="text-align: left"/>
<col style="text-align: left"/>
</colgroup>
<thead>
<tr>
<th style="text-align: left">
parametro di GRUB
</th>
<th style="text-align: left">
significato
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<code class="literal">root</code>
</td>
<td style="text-align: left">
usa la terza partizione sul primo disco fisso indicandola come
"<code class="literal">(hd0,2)</code>" in GRUB legacy o come
"<code class="literal">(hd0,3)</code>" in GRUB 2
</td>
</tr>
<tr>
<td style="text-align: left">
<code class="literal">kernel</code>
</td>
<td style="text-align: left">
usa il kernel che si trova in "<code class="literal">/vmlinuz</code>" con i parametri
"<code class="literal">root=/dev/hda3 ro</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
<code class="literal">initrd</code>
</td>
<td style="text-align: left">
usa l'immagine <a class="ulink" href="http://it.wikipedia.org/wiki/Initrd">initrd/initramfs</a> che
si trova in "<code class="literal">/initrd.img</code>"
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Nota]" src="images/note.png"/>
</td>
<th align="left">Nota</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Il valore per il numero di partizione usato dal programma GRUB Legacy è
minore di uno rispetto a quello normale usato dal kernel Linux e dagli
strumenti di utilità. il programma GRUB 2 ha risolto questo problema.</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Per identificare un particolare dispositivo a blocchi si può usare il suo
<a class="ulink" href="http://en.wikipedia.org/wiki/Universally_Unique_Identifier">UUID</a> (vedere <a class="xref" href="ch09.it.html#_accessing_partition_using_uuid" title="9.5.3. Accedere alle partizioni usando UUID">Sezione 9.5.3, «Accedere alle partizioni usando UUID»</a>) invece del suo nome file come
"<code class="literal">/dev/hda3</code>", ad esempio
"<code class="literal">root=UUID=81b289d5-4341-4003-9602-e254a17ac232 ro</code>".</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Se viene usato <a class="ulink" href="http://en.wikipedia.org/wiki/GRUB">GRUB</a>, il parametro di avvio del
kernel viene impostato in <code class="literal">/boot/grub/grub.cfg</code>. Nei
sistemi Debian non si dovrebbe modificare direttamente il file
<code class="literal">/boot/grub/grub.cfg</code>. Si dovrebbe modificare il valore
<code class="literal">GRUB_CMDLINE_LINUX_DEFAULT</code> in
<code class="literal">/etc/default/grub</code> ed eseguire
<span class="citerefentry"><span class="refentrytitle">update-grub</span>(8)</span>
per aggiornare <code class="literal">/boot/grub/grub.cfg</code>.</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Si può avviare un bootloader da un altro bootloader usando una tecnica
chiamata <a class="ulink" href="http://en.wikipedia.org/wiki/Chain_loading">caricamento a catena</a>.</p>
</td>
</tr>
</table>
</div>
<p>Vedere "<code class="literal">info grub</code>" e
<span class="citerefentry"><span class="refentrytitle">grub-install</span>(8)</span>.</p>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_stage_3_the_mini_debian_system"/>3.1.3. Stadio 3: il mini-sistema Debian</h3>
</div>
</div>
</div>
<p>Il mini-sistema Debian è il terzo stadio del processo di avvio che viene
iniziato dal bootloader. Esegue il kernel del sistema con il suo filesystem
root in memoria. Questo è uno stadio opzionale preparatorio del processo di
avvio.</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Nota]" src="images/note.png"/>
</td>
<th align="left">Nota</th>
</tr>
<tr>
<td align="left" valign="top">
<p>L'espressione "sistema Debian mini" è stata coniata per descrivere il terzo
stadio del processo di avvio in questo documento. Normalmente ci si
riferisce a questo sistema come sistema <a class="ulink" href="http://it.wikipedia.org/wiki/Initrd">initrd</a>
o initramfs. Un sistema simile in memoria è usato dall'<a class="ulink" href="https://www.debian.org/devel/debian-installer/">installatore Debian</a>.</p>
</td>
</tr>
</table>
</div>
<p>The "<code class="literal">/init</code>" program is executed as the first program in
this root filesystem on the memory. It is a program which initializes the
kernel in user space and hands control over to the next stage. This
mini-Debian system offers flexibility to the boot process such as adding
kernel modules before the main boot process or mounting the root filesystem
as an encrypted one.</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
The "<code class="literal">/init</code>" program is a shell script program if
initramfs was created by <code class="literal">initramfs-tools</code>. <span class="strong"><strong> You can interrupt this part of the boot process to gain root
shell by providing "<code class="literal">break=init</code>" etc. to the kernel boot
parameter. See the "<code class="literal">/init</code>" script for more break
conditions. This shell environment is sophisticated enough to make a good
inspection of your machine's hardware. </strong></span> Commands available in
this mini-Debian system are stripped down ones and mainly provided by a GNU
tool called
<span class="citerefentry"><span class="refentrytitle">busybox</span>(1)</span>.
</p>
</li>
<li class="listitem">
<p>
The "<code class="literal">/init</code>" program is a binary
<code class="literal">systemd</code> program if initramfs was created by
<code class="literal">dracut</code>. ** Commands available in this mini-Debian system
are stripped down
<span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span>
environment.
</p>
</li>
</ul>
</div>
<div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Caution">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Attenzione]" src="images/caution.png"/>
</td>
<th align="left">Attenzione</th>
</tr>
<tr>
<td align="left" valign="top">
<p>È necessario usare l'opzione "<code class="literal">-n</code>" per il comando
<code class="literal">mount</code> quando si è nel filesystem root in sola lettura.</p>
</td>
</tr>
</table>
</div>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_stage_4_the_normal_debian_system"/>3.1.4. Stadio 4: il normale sistema Debian</h3>
</div>
</div>
</div>
<p>Il sistema Debian normale è il quarto stadio del processo di avvio che viene
iniziato dal mini-sistema Debian. Il kernel di sistema del mini-sistema
Debian continua ad essere in esecuzione anche in questo ambiente. Il
filesystem root viene cambiato da quello in memoria all'effettivo filesystem
sul disco fisso.</p>
<p>Il programma <a class="ulink" href="http://it.wikipedia.org/wiki/Init">init</a> viene eseguito come primo
programma con PID=1 per effettuare il processo principale di avvio di far
partire molti programmi. Il percorso di file predefinito per il programma
init è «<code class="literal">/sbin/init</code>», ma può essere cambiato con un
parametro di avvio del kernel come in
«<code class="literal">init=/percorso/del/programma_init</code>».</p>
<p>Il programma init predefinito ha subito cambiamenti:</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
Prima di <code class="literal">squeeze</code> Debian usava il semplice init in stile
<a class="ulink" href="http://it.wikipedia.org/wiki/UNIX_System_V">SysV</a>.
</p>
</li>
<li class="listitem">
<p>
Debian <code class="literal">wheezy</code> migliora l'init in stile SysV ordinando la
sequenza con intestazioni LSB e avviando gli script di avvio in parallelo.
</p>
</li>
<li class="listitem">
<p>
Debian <code class="literal">jessie</code> è passata come init predefinito a <a class="ulink" href="http://en.wikipedia.org/wiki/Systemd">systemd</a> per l'inizializzazione pilotata da eventi e
in parallelo.
</p>
</li>
</ul>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Si può verificare quale è l'effettivo comando init nel proprio sistema con
il comando «<code class="literal">ps --pid 1 -f</code>».</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>"<code class="literal">/sbin/init</code>" is symlinked to
"<code class="literal">/lib/systemd/systemd</code>" after Debian
<code class="literal">jessie</code>.</p>
</td>
</tr>
</table>
</div>
<div class="table">
<a id="listofbootutilitrthedebiansystem"/>
<p class="title">
<strong>Tabella 3.3. Elenco di utilità di avvio per il sistema Debian</strong>
</p>
<div class="table-contents">
<table class="table" summary="Elenco di utilità di avvio per il sistema Debian" border="1">
<colgroup>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
</colgroup>
<thead>
<tr>
<th style="text-align: left">
pacchetto
</th>
<th style="text-align: left">
popcon
</th>
<th style="text-align: left">
dimensione
</th>
<th style="text-align: left">
descrizione
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/systemd">
<code class="literal">systemd</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=systemd">V:703, I:805</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/systemd.html">11933</a>
</td>
<td style="text-align: left">
demone
<span class="citerefentry"><span class="refentrytitle">init</span>(8)</span>
basato su eventi per concorrenza (alternativa a <code class="literal">sysvinit</code>)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/systemd-sysv">
<code class="literal">systemd-sysv</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=systemd-sysv">V:684, I:798</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/systemd-sysv.html">112</a>
</td>
<td style="text-align: left">
the manual pages and links needed for <code class="literal">systemd</code> to replace
<code class="literal">sysvinit</code>
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/systemd-cron">
<code class="literal">systemd-cron</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=systemd-cron">V:0, I:1</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/systemd-cron.html">133</a>
</td>
<td style="text-align: left"><code class="literal">systemd</code> units to provide <code class="literal">cron</code> daemon
and <code class="literal">anacron</code> functionality
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/init-system-helpers">
<code class="literal">init-system-helpers</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=init-system-helpers">V:704, I:826</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/i/init-system-helpers.html">129</a>
</td>
<td style="text-align: left">
helper tools for switching between <code class="literal">sysvinit</code> and
<code class="literal">systemd</code>
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/initscripts">
<code class="literal">initscripts</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=initscripts">V:284, I:667</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/i/initscripts.html">205</a>
</td>
<td style="text-align: left">
script per inizializzare ed arrestare il sistema
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/sysvinit-core">
<code class="literal">sysvinit-core</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=sysvinit-core">V:13, I:17</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/sysvinit-core.html">225</a>
</td>
<td style="text-align: left">
utilità
<span class="citerefentry"><span class="refentrytitle">init</span>(8)</span>
in stile System-V
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/sysv-rc">
<code class="literal">sysv-rc</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=sysv-rc">V:477, I:673</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/sysv-rc.html">123</a>
</td>
<td style="text-align: left">
meccanismo di cambiamento del runlevel in stile System-V
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/sysvinit-utils">
<code class="literal">sysvinit-utils</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=sysvinit-utils">V:791, I:999</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/sysvinit-utils.html">110</a>
</td>
<td style="text-align: left">
utilità in stile System-V
(<span class="citerefentry"><span class="refentrytitle">startpar</span>(8)</span>,
<span class="citerefentry"><span class="refentrytitle">bootlogd</span>(8)</span>,
…)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/lsb-base">
<code class="literal">lsb-base</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=lsb-base">V:877, I:999</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/l/lsb-base.html">49</a>
</td>
<td style="text-align: left">funzionalità di script init <a class="ulink" href="http://it.wikipedia.org/wiki/Linux_Standard_Base">Linux Standard
Base</a> 3.2
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/insserv">
<code class="literal">insserv</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=insserv">V:539, I:660</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/i/insserv.html">140</a>
</td>
<td style="text-align: left">
strumento per organizzare la sequenza di avvio usando dipendenze LSB negli
script init.d
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/uswsusp">
<code class="literal">uswsusp</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=uswsusp">V:4, I:11</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/u/uswsusp.html">699</a>
</td>
<td style="text-align: left">
strumenti per usare la sospensione software in spazio utente fornita da
Linux
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/kexec-tools">
<code class="literal">kexec-tools</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=kexec-tools">V:1, I:8</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/k/kexec-tools.html">270</a>
</td>
<td style="text-align: left">
strumento kexec per riavvii
<span class="citerefentry"><span class="refentrytitle">kexec</span>(8)</span>
(riavvio a caldo)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/systemd-bootchart">
<code class="literal">systemd-bootchart</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=systemd-bootchart">V:0, I:0</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/s/systemd-bootchart.html">122</a>
</td>
<td style="text-align: left">
analizzatore delle prestazioni del processo di avvio
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/bootchart2">
<code class="literal">bootchart2</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=bootchart2">V:0, I:1</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/b/bootchart2.html">94</a>
</td>
<td style="text-align: left">
analizzatore delle prestazioni del processo di avvio
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/pybootchartgui">
<code class="literal">pybootchartgui</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=pybootchartgui">V:0, I:1</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/p/pybootchartgui.html">177</a>
</td>
<td style="text-align: left">
analizzatore delle prestazioni del processo di avvio (visualizzazione)
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/mingetty">
<code class="literal">mingetty</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=mingetty">V:0, I:3</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/m/mingetty.html">35</a>
</td>
<td style="text-align: left">
<span class="citerefentry"><span class="refentrytitle">getty</span>(8)</span>
solo console
</td>
</tr>
<tr>
<td style="text-align: left">
<a class="ulink" href="http://packages.debian.org/sid/mgetty">
<code class="literal">mgetty</code> </a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://qa.debian.org/popcon.php?package=mgetty">V:0, I:1</a>
</td>
<td style="text-align: left">
<a class="ulink" href="http://packages.qa.debian.org/m/mgetty.html">301</a>
</td>
<td style="text-align: left">
rimpiazzio di
<span class="citerefentry"><span class="refentrytitle">getty</span>(8)</span>
per smart modem
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Vedere la <a class="ulink" href="https://wiki.debian.org/BootProcessSpeedup">pagina del Wiki Debian
sulla velocizzazione del processo di avvio</a> per i più recenti
suggerimenti su come velocizzare il processo di avvio.</p>
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title"><a id="_systemd_init"/>3.2. Systemd init</h2>
</div>
</div>
</div>
<p>This section describes how system is started by the
<span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span>
program with <code class="literal">PID=1</code> (i.e., init process).</p>
<p>The <code class="literal">systemd</code> init process spawns processes in parallel
based on the unit configuration files (see
<span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span>)
which are written in declarative style instead of SysV-like procedural
style. These are loaded from a set of paths (see
<span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span>)
as follows:</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
"<code class="literal">/lib/systemd/system</code>": OS default configuration files
</p>
</li>
<li class="listitem">
<p>
"<code class="literal">/etc/systemd/system</code>": system administrator configuration
files which override the OS default configuration files
</p>
</li>
<li class="listitem">
<p>
"<code class="literal">/run/systemd/system</code>": run-time generated configuration
files which override the installed configuration files
</p>
</li>
</ul>
</div>
<p>Their inter-dependencies are specified by the directives
"<code class="literal">Wants=</code>", "<code class="literal">Requires=</code>",
"<code class="literal">Before=</code>", "<code class="literal">After=</code>", … (see "MAPPING
OF UNIT PROPERTIES TO THEIR INVERSES" in
<span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span>).
The resource controls are also defined (see
<span class="citerefentry"><span class="refentrytitle">systemd.resource-control</span>(5)</span>).</p>
<p>The suffix of the unit configuration file encodes their types as:</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p><span class="strong"><strong>*.service</strong></span> describes the process
controlled and supervised by <code class="literal">systemd</code>. See
<span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.device</strong></span> describes the device exposed in
the
<span class="citerefentry"><span class="refentrytitle">sysfs</span>(5)</span>
as
<span class="citerefentry"><span class="refentrytitle">udev</span>(7)</span>
device tree. See
<span class="citerefentry"><span class="refentrytitle">systemd.device</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.mount</strong></span> describes the file system mount
point controlled and supervised by <code class="literal">systemd</code>. See
<span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.automount</strong></span> describes the file system
auto mount point controlled and supervised by
<code class="literal">systemd</code>. See
<span class="citerefentry"><span class="refentrytitle">systemd.automount</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.swap</strong></span> describes the swap device or file
controlled and supervised by <code class="literal">systemd</code>. See
<span class="citerefentry"><span class="refentrytitle">systemd.swap</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.path</strong></span> describes the path monitored by
<code class="literal">systemd</code> for path-based activation. See
<span class="citerefentry"><span class="refentrytitle">systemd.path</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.socket</strong></span> describes the socket controlled
and supervised by <code class="literal">systemd</code> for socket-based
activation. See
<span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.timer</strong></span> describes the timer controlled
and supervised by <code class="literal">systemd</code> for timer-based activation. See
<span class="citerefentry"><span class="refentrytitle">systemd.timer</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.slice</strong></span> manages resources with the
<span class="citerefentry"><span class="refentrytitle">cgroups</span>(7)</span>.
See
<span class="citerefentry"><span class="refentrytitle">systemd.slice</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.scope</strong></span> is created programmatically using
the bus interfaces of <code class="literal">systemd</code> to manages a set of system
processes. See
<span class="citerefentry"><span class="refentrytitle">systemd.scope</span>(5)</span>.
</p>
</li>
<li class="listitem">
<p><span class="strong"><strong>*.target</strong></span> groups other unit configuration
files to create the synchronization point during start-up. See
<span class="citerefentry"><span class="refentrytitle">systemd.target</span>(5)</span>.
</p>
</li>
</ul>
</div>
<p>Upon system start up (i.e., init), the <code class="literal">systemd</code> process
tries to start the "<code class="literal">/lib/systemd/system/default.target</code>
(normally symlinked to "<code class="literal">graphical.target</code>"). First, some
special target units (see
<span class="citerefentry"><span class="refentrytitle">systemd.special</span>(7)</span>)
such as "<code class="literal">local-fs.target</code>",
"<code class="literal">swap.target</code>" and "<code class="literal">cryptsetup.target</code>"
are pulled in to mount the filesystems. Then, other target units are also
pulled in by the target unit dependencies. For details, read
<span class="citerefentry"><span class="refentrytitle">bootup</span>(7)</span>.</p>
<p><code class="literal">systemd</code> offers backward compatibility features.
SysV-style boot scripts in
"<code class="literal">/etc/init.d/rc[0123456S].d/[KS]<name></code>" are still
parsed and
<span class="citerefentry"><span class="refentrytitle">telinit</span>(8)</span>
is translated into systemd unit activation requests.</p>
<div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Caution">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Attenzione]" src="images/caution.png"/>
</td>
<th align="left">Attenzione</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Emulated runlevel 2 to 4 are all symlinked to the same
"<code class="literal">multi-user.target</code>".</p>
</td>
</tr>
</table>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_the_hostname"/>3.2.1. Il nome host</h3>
</div>
</div>
</div>
<p>The kernel maintains the system <span class="strong"><strong>hostname</strong></span>. The system unit started by
<code class="literal">systemd-hostnamed.service</code> sets the system hostname at
boot time to the name stored in "<code class="literal">/etc/hostname</code>". This
file should contain <span class="strong"><strong>only</strong></span> the system
hostname, not a fully qualified domain name.</p>
<p>Per visualizzare il nome host attuale eseguire
<span class="citerefentry"><span class="refentrytitle">hostname</span>(1)</span>
senza alcun argomento.</p>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_the_filesystem"/>3.2.2. Il filesystem</h3>
</div>
</div>
</div>
<p>The mount options of normal disk and network filesystems are set in
"<code class="literal">/etc/fstab</code>". See
<span class="citerefentry"><span class="refentrytitle">fstab</span>(5)</span>
and <a class="xref" href="ch09.it.html#_optimization_of_filesystem_by_mount_options" title="9.5.7. Ottimizzare il file system con opzioni di mount">Sezione 9.5.7, «Ottimizzare il file system con opzioni di mount»</a>.</p>
<p>The configuration of the encrypted filesystem is set in
"<code class="literal">/etc/crypttab</code>". See
<span class="citerefentry"><span class="refentrytitle">crypttab</span>(5)</span></p>
<p>The configuration of software RAID with
<span class="citerefentry"><span class="refentrytitle">mdadm</span>(8)</span>
is set in "<code class="literal">/etc/mdadm/mdadm.conf</code>". See
<span class="citerefentry"><span class="refentrytitle">mdadm.conf</span>(5)</span>.</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Warning">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Avvertimento]" src="images/warning.png"/>
</td>
<th align="left">Avvertimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Dopo aver montato tutti i filesystem, i file temporanei in
"<code class="literal">/tmp</code>", "<code class="literal">/var/lock</code>" e
"<code class="literal">/var/run</code>" vengono ripuliti ad ogni avvio.</p>
</td>
</tr>
</table>
</div>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_network_interface_initialization"/>3.2.3. Inizializzazione delle interfacce di rete</h3>
</div>
</div>
</div>
<p>Network interfaces are typically initialized in
"<code class="literal">networking.service</code>" for the <code class="literal">lo</code>
interface and "<code class="literal">NetworkManager.service</code>" for other
interfaces on modern Debian desktop system under <code class="literal">systemd</code>.</p>
<p>See <a class="xref" href="ch05.it.html" title="Capitolo 5. Impostazione della rete">Capitolo 5, <em>Impostazione della rete</em></a> for how to configure them.</p>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_the_kernel_message"/>3.2.4. I messaggi del kernel</h3>
</div>
</div>
</div>
<p>The kernel error message displayed to the console can be configured by
setting its threshold level.</p>
<pre class="screen"># dmesg -n3</pre>
<div class="table">
<a id="listofkernelerrorlevels"/>
<p class="title">
<strong>Tabella 3.4. Elenco dei livelli di errore del kernel</strong>
</p>
<div class="table-contents">
<table class="table" summary="Elenco dei livelli di errore del kernel" border="1">
<colgroup>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
</colgroup>
<thead>
<tr>
<th style="text-align: left">
valore del livello di errore
</th>
<th style="text-align: left">
nome del livello di errore
</th>
<th style="text-align: left">
significato
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
0
</td>
<td style="text-align: left">
KERN_EMERG
</td>
<td style="text-align: left">
il sistema è inutilizzabile
</td>
</tr>
<tr>
<td style="text-align: left">
1
</td>
<td style="text-align: left">
KERN_ALERT
</td>
<td style="text-align: left">
bisogna agire immediatamente
</td>
</tr>
<tr>
<td style="text-align: left">
2
</td>
<td style="text-align: left">
KERN_CRIT
</td>
<td style="text-align: left">
condizione critica
</td>
</tr>
<tr>
<td style="text-align: left">
3
</td>
<td style="text-align: left">
KERN_ERR
</td>
<td style="text-align: left">
condizione di errore
</td>
</tr>
<tr>
<td style="text-align: left">
4
</td>
<td style="text-align: left">
KERN_WARNING
</td>
<td style="text-align: left">
condizione di avvertimento
</td>
</tr>
<tr>
<td style="text-align: left">
5
</td>
<td style="text-align: left">
KERN_NOTICE
</td>
<td style="text-align: left">
condizione normale ma significativa
</td>
</tr>
<tr>
<td style="text-align: left">
6
</td>
<td style="text-align: left">
KERN_INFO
</td>
<td style="text-align: left">
messaggio informativo
</td>
</tr>
<tr>
<td style="text-align: left">
7
</td>
<td style="text-align: left">
KERN_DEBUG
</td>
<td style="text-align: left">
messaggio a livello di debug
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_the_system_message"/>3.2.5. I messaggi di sistema</h3>
</div>
</div>
</div>
<p>Under <code class="literal">systemd</code>, both kernel and system messages are logged
by the journal service <code class="literal">systemd-journald.service</code> (a.k.a
<code class="literal">journald</code>) either into a persistent binary data below
"<code class="literal">/var/log/journal</code>" or into a volatile binary data below
"<code class="literal">/run/log/journal/</code>". These binary log data are accessed
by the
<span class="citerefentry"><span class="refentrytitle">journalctl</span>(1)</span>
command.</p>
<p>Under <code class="literal">systemd</code>, the system logging utility
<span class="citerefentry"><span class="refentrytitle">rsyslogd</span>(8)</span>
changes its behavior to read the volatile binary log data (instead of
pre-systemd default "<code class="literal">/dev/log</code>") and to create traditional
permanent ASCII system log data.</p>
<p>I messaggi di sistema possono essere personalizzati da
"<code class="literal">/etc/default/rsyslog</code>" e
"<code class="literal">/etc/rsyslog.conf</code>" sia per il file di registro sia per
la visualizzazione a schermo. Vedere
<span class="citerefentry"><span class="refentrytitle">rsyslogd</span>(8)</span>
e
<span class="citerefentry"><span class="refentrytitle">rsyslog.conf</span>(5)</span>.
Vedere anche <a class="xref" href="ch09.it.html#_log_analyzer" title="9.2.2. Analizzatori di registro">Sezione 9.2.2, «Analizzatori di registro»</a>.</p>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_system_management_under_systemd"/>3.2.6. System management under systemd</h3>
</div>
</div>
</div>
<p>The <code class="literal">systemd</code> offers not only init system but also generic
system management functionalities such as journal logging, login management,
time management, network management. etc..</p>
<p>The
<span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span>
is managed by several commands:</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
the
<span class="citerefentry"><span class="refentrytitle">systemctl</span>(1)</span>
command controls the <code class="literal">systemd</code> system and service manager
(CLI),
</p>
</li>
<li class="listitem">
<p>
the
<span class="citerefentry"><span class="refentrytitle">systemsdm</span>(1)</span>
command controls the <code class="literal">systemd</code> system and service manager
(GUI),
</p>
</li>
<li class="listitem">
<p>
the
<span class="citerefentry"><span class="refentrytitle">journalctl</span>(1)</span>
command queries the <code class="literal">systemd</code> journal,
</p>
</li>
<li class="listitem">
<p>
the
<span class="citerefentry"><span class="refentrytitle">loginctl</span>(1)</span>
command controls the <code class="literal">systemd</code> login manager, and
</p>
</li>
<li class="listitem">
<p>
the
<span class="citerefentry"><span class="refentrytitle">systemd-analyze</span>(1)</span>
analyzes system boot-up performance.
</p>
</li>
</ul>
</div>
<p>Here are a list of typical <code class="literal">systemd</code> management command
snippets. For the exact meanings, please read the pertinent manpages.</p>
<div class="table">
<a id="listoftypicalsystcommandsnippets"/>
<p class="title">
<strong>Tabella 3.5. List of typical <code class="literal">systemd</code> management command snippets</strong>
</p>
<div class="table-contents">
<table class="table" summary="List of typical systemd management command snippets" border="1">
<colgroup>
<col style="text-align: left"/>
<col style="text-align: left"/>
<col style="text-align: left"/>
</colgroup>
<thead>
<tr>
<th style="text-align: left">
Operation
</th>
<th style="text-align: left">
Type
</th>
<th style="text-align: left">
Command snippets
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left">
GUI for service manager
</td>
<td style="text-align: left">
GUI
</td>
<td style="text-align: left">
"<code class="literal">systemadm</code>" (<code class="literal">systemd-ui</code> package)
</td>
</tr>
<tr>
<td style="text-align: left">
List all target unit configuration
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-units --type=target</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
List all service unit configuration
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-units --type=service</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
List all unit configuration types
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-units --type=help</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
List all socket units in memory
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-sockets</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
List all timer units in memory
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-timers</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Start "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl start $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Stop "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl stop $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Reload service-specific configuration
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl reload $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Stop and start all "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl restart $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Start "<code class="literal">$unit</code>" and stop all others
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl isolate $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Switch to "<code class="literal">graphical</code>" (GUI system)
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl isolate graphical</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Switch to "<code class="literal">multi-user</code>" (CLI system)
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl isolate multi-user</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Switch to "<code class="literal">rescue</code>" (single user CLI system)
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl isolate rescue</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Send kill signal to "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl kill $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Send kill signal to "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl kill $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Check if "<code class="literal">$unit</code>" service is active
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl is-active $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Check if "<code class="literal">$unit</code>" service is failed
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl is-failed $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Check status of "<code class="literal">$unit|$PID|device</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl status $unit|$PID|$device</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Show properties of "<code class="literal">$unit|$job</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl show $unit|$job</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Reset failed "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl reset-failed $unit"</code>
</td>
</tr>
<tr>
<td style="text-align: left">
List dependency of all unit services
</td>
<td style="text-align: left">
Unit
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-dependencies --all</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
List unit files installed on the system
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl list-unit-files</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Enable "<code class="literal">$unit</code>" (add symlink)
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl enable $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Disable "<code class="literal">$unit</code>" (remove symlink)
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl disable $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Unmask "<code class="literal">$unit</code>" (remove symlink to
"<code class="literal">/dev/null</code>")
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl unmask $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Mask "<code class="literal">$unit</code>" (add symlink to
"<code class="literal">/dev/null</code>")
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl mask $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Get default-target setting
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl get-default</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Set default-target to "<code class="literal">graphical</code>" (GUI system)
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl set-default graphical</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Set default-target to "<code class="literal">multi-user</code>" (CLI system)
</td>
<td style="text-align: left">
Unit file
</td>
<td style="text-align: left">
"<code class="literal">systemctl set-default multi-user</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Show job environment
</td>
<td style="text-align: left">
Environment
</td>
<td style="text-align: left">
"<code class="literal">systemctl show-environment</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Set job environment "<code class="literal">variable</code>" to
"<code class="literal">value</code>"
</td>
<td style="text-align: left">
Environment
</td>
<td style="text-align: left">
"<code class="literal">systemctl set-environment variable=value</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Unset job environment "<code class="literal">variable</code>"
</td>
<td style="text-align: left">
Environment
</td>
<td style="text-align: left">
"<code class="literal">systemctl unset-environment variable</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Reload all unit files and daemons
</td>
<td style="text-align: left">
Lifecycle
</td>
<td style="text-align: left">
"<code class="literal">systemctl daemon-reload</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Shut down the system
</td>
<td style="text-align: left">
System
</td>
<td style="text-align: left">
"<code class="literal">systemctl poweroff</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Shut down and reboot the system
</td>
<td style="text-align: left">
System
</td>
<td style="text-align: left">
"<code class="literal">systemctl reboot</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Suspend the system
</td>
<td style="text-align: left">
System
</td>
<td style="text-align: left">
"<code class="literal">systemctl suspend</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Hibernate the system
</td>
<td style="text-align: left">
System
</td>
<td style="text-align: left">
"<code class="literal">systemctl hibernate</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
View job log of "<code class="literal">$unit</code>"
</td>
<td style="text-align: left">
Journal
</td>
<td style="text-align: left">
"<code class="literal">journalctl -u $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
View job log of "<code class="literal">$unit</code>" ("<code class="literal">tail -f</code>"
style)
</td>
<td style="text-align: left">
Journal
</td>
<td style="text-align: left">
"<code class="literal">journalctl -u $unit -f</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Show time spent for each initialization steps
</td>
<td style="text-align: left">
Analyze
</td>
<td style="text-align: left">
"<code class="literal">systemd-analyze time</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
List of all units by the time to initialize
</td>
<td style="text-align: left">
Analyze
</td>
<td style="text-align: left">
"<code class="literal">systemd-analyze blame</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Load and detect errors in "<code class="literal">$unit</code>" file
</td>
<td style="text-align: left">
Analyze
</td>
<td style="text-align: left">
"<code class="literal">systemd-analyze verify $unit</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Track boot process by the
<span class="citerefentry"><span class="refentrytitle">cgroups</span>(7)</span>
</td>
<td style="text-align: left">
Cgroup
</td>
<td style="text-align: left">
"<code class="literal">systemd-cgls</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Track boot process by the
<span class="citerefentry"><span class="refentrytitle">cgroups</span>(7)</span>
</td>
<td style="text-align: left">
Cgroup
</td>
<td style="text-align: left">
"<code class="literal">ps xawf -eo pid,user,cgroup,args</code>"
</td>
</tr>
<tr>
<td style="text-align: left">
Track boot process by the
<span class="citerefentry"><span class="refentrytitle">cgroups</span>(7)</span>
</td>
<td style="text-align: left">
Cgroup
</td>
<td style="text-align: left">
Read <a class="ulink" href="http://en.wikipedia.org/wiki/Sysfs">sysfs</a> under
"<code class="literal">/sys/fs/cgroup/systemd/</code>"
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<p>Here, "<code class="literal">$unit</code>" in the above examples may be a single unit
name (suffix such as <code class="literal">.service</code> and
<code class="literal">.target</code> are optional) or, in many cases, multiple unit
specifications (shell-style globs "<code class="literal">*</code>",
"<code class="literal">?</code>", "<code class="literal">[]</code>" using
<span class="citerefentry"><span class="refentrytitle">fnmatch</span>(3)</span>
which will be matched against the primary names of all units currently in
memory).</p>
<p>System state changing commands in the above examples are typically preceded
by the "<code class="literal">sudo</code>" to attain the required administrative
privilege.</p>
<p>The output of the "<code class="literal">systemctl status $unit|$PID|$device</code>"
uses color of the dot ("●") to summarize the unit state at a glance.</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>
White "●" indicates an "inactive" or "deactivating" state.
</p>
</li>
<li class="listitem">
<p>
Red "●" indicates a "failed" or "error" state.
</p>
</li>
<li class="listitem">
<p>
Green "●" indicates an "active", "reloading" or "activating" state.
</p>
</li>
</ul>
</div>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_customizing_systemd"/>3.2.7. Customizing systemd</h3>
</div>
</div>
</div>
<p>With default installation, many network services (see <a class="xref" href="ch06.it.html" title="Capitolo 6. Applicazioni per la rete">Capitolo 6, <em>Applicazioni per la rete</em></a>) are started as daemon processes after
<code class="literal">network.target</code> at boot time by
<code class="literal">systemd</code>. The "<code class="literal">sshd</code>" is no exception.
Let's change this to on-demand start of "<code class="literal">sshd</code>" as a
customization example.</p>
<p>First, disable system installed service unit.</p>
<pre class="screen"> $ sudo systemctl stop sshd.service
$ sudo systemctl mask sshd.service</pre>
<p>The on-demand socket activation system of the classic Unix services was
through the <code class="literal">indetd</code> superserver. Under
<code class="literal">systemd</code>, the equivalent can be enabled by adding
<span class="strong"><strong>*.socket</strong></span> and <span class="strong"><strong>*.service</strong></span> unit configuration files.</p>
<p><code class="literal">sshd.socket</code> for specifying a socket to listen on</p>
<pre class="screen">[Unit]
Description=SSH Socket for Per-Connection Servers
[Socket]
ListenStream=22
Accept=yes
[Install]
WantedBy=sockets.target</pre>
<p><code class="literal">sshd@.service</code> as the matching service file of
<code class="literal">sshd.socket</code></p>
<pre class="screen">[Unit]
Description=SSH Per-Connection Server
[Service]
ExecStart=-/usr/sbin/sshd -i
StandardInput=socket</pre>
<p>Then reload.</p>
<pre class="screen"> $ sudo systemctl daemon-reload</pre>
</div>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title"><a id="_the_udev_system"/>3.3. Il sistema udev</h2>
</div>
</div>
</div>
<p>Per i kernel Linux 2.6 e successivi, <a class="ulink" href="http://en.wikipedia.org/wiki/Udev">il sistema
udev</a> fornisce un meccanismo di rilevazione e inizializzazione
automatiche dell'hardware (vedere
<span class="citerefentry"><span class="refentrytitle">udev</span>(7)</span>).
Per ogni dispositivo rilevato dal kernel, il sistema udev avvia un processo
utente che usa le informazioni del filesystem <a class="ulink" href="http://en.wikipedia.org/wiki/Sysfs">sysfs</a> (vedere <a class="xref" href="ch01.it.html#_procfs_and_sysfs" title="1.2.12. procfs e sysfs">Sezione 1.2.12, «procfs e sysfs»</a>),
carica, usando
<span class="citerefentry"><span class="refentrytitle">modprobe</span>(8)</span>
(vedere <a class="xref" href="ch03.it.html#_the_kernel_module_initialization" title="3.3.1. L'inizializzazione dei moduli del kernel">Sezione 3.3.1, «L'inizializzazione dei moduli del kernel»</a>), i moduli del
kernel necessari per il supporto del dispositivo e crea i nodi di device
corrispondenti.</p>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Se, per una qualche ragione
"<code class="literal">/lib/modules/<versione-kernel>/modules.dep</code> non
viene generato in modo appropriato dal
<span class="citerefentry"><span class="refentrytitle">depmod</span>(8)</span>,
i moduli non possono essere caricati come dovuto dal sistema udev. Per
risolvere il problema eseguire "<code class="literal">depmod -a</code>".</p>
</td>
</tr>
</table>
</div>
<p>Il nome dei nodi di device può essere configurato dai file di regole di udev
in "<code class="literal">/etc/udev/rules.d/</code>". Le regole predefinite attuali
tendono a creare nomi generati dinamicamente che hanno come risultato nomi
di device non fissi, tranne che per dispositivi CD e di rete. Aggiungendo le
proprie regole personalizzate, in modo simile a quelle per i dispositivi CD
e di rete, si possono creare nomi di device statici anche per altri
dispositivi, come chiavette USB. Vedere "<a class="ulink" href="http://www.reactivated.net/writing_udev_rules.html">Scrivere regole udev</a>" o
"<code class="literal">/usr/share/doc/udev/writing_udev_rules/index.html</code>".</p>
<p>Dato che il sistema udev è in qualche modo in costante evoluzione, in questo
documento sono fornite informazioni base, lasciando i dettagli ad altra
documentazione.</p>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Per le regole di montaggio in "<code class="literal">/etc/fstab</code>", non è
necessario che i nodi di device siano statici. Si possono usare gli <a class="ulink" href="http://en.wikipedia.org/wiki/Universally_Unique_Identifier">UUID</a> per montare i dispositivi, al posto dei nomi di
device come "<code class="literal">/dev/sda</code>". Vedere <a class="xref" href="ch09.it.html#_accessing_partition_using_uuid" title="9.5.3. Accedere alle partizioni usando UUID">Sezione 9.5.3, «Accedere alle partizioni usando UUID»</a>.</p>
</td>
</tr>
</table>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="_the_kernel_module_initialization"/>3.3.1. L'inizializzazione dei moduli del kernel</h3>
</div>
</div>
</div>
<p>Il programma
<span class="citerefentry"><span class="refentrytitle">modprobe</span>(8)</span>
permette di configurare il kernel Linux in esecuzione da processi utente,
aggiungendo e rimuovendo moduli del kernel. Il sistema udev (vedere <a class="xref" href="ch03.it.html#_the_udev_system" title="3.3. Il sistema udev">Sezione 3.3, «Il sistema udev»</a>) automatizza la sua invocazione per facilitare
l'inizializzazione dei moduli del kernel.</p>
<p>Ci sono moduli non-hardware e speciali moduli con driver hardware, come
quelli elencati in seguito, che devono essere precaricati elencandoli nel
file "<code class="literal">/etc/modules</code>" (vedere
<span class="citerefentry"><span class="refentrytitle">modules</span>(5)</span>).</p>
<div class="itemizedlist">
<ul class="itemizedlist">
<li class="listitem">
<p>moduli <a class="ulink" href="http://it.wikipedia.org/wiki/TUN/TAP">TUN/TAP</a> che forniscono device virtuali
di rete Point-to-Point (TUN) e device virtuali di rete Ethernet (TAP),
</p>
</li>
<li class="listitem">
<p>moduli <a class="ulink" href="http://it.wikipedia.org/wiki/Netfilter">netfilter</a> che forniscono
funzionalità di firewall netfilter
(<span class="citerefentry"><span class="refentrytitle">iptables</span>(8)</span>,
<a class="xref" href="ch05.it.html#_netfilter_infrastructure" title="5.10. Infrastruttura netfilter">Sezione 5.10, «Infrastruttura netfilter»</a> e
</p>
</li>
<li class="listitem">
<p>moduli driver <a class="ulink" href="http://it.wikipedia.org/wiki/Watchdog">watchdog timer</a>.
</p>
</li>
</ul>
</div>
<p>I file di configurazione per il programma
<span class="citerefentry"><span class="refentrytitle">modprobe</span>(8)</span>
sono contenuti nella directory "<code class="literal">/etc/modprobes.d/</code>", come
spiegato in
<span class="citerefentry"><span class="refentrytitle">modprobe.conf</span>(5)</span>.
(Se si desidera evitare l'autocaricamento di alcuni moduli del kernel,
considerare la loro aggiunta nella lista nera nel file
"<code class="literal">/etc/modprobes.d/blacklist</code>".)</p>
<p>Il file "<code class="literal">/lib/modules/<versione>/modules.dep</code>"
generato dal programma
<span class="citerefentry"><span class="refentrytitle">depmod</span>(8)</span>
descrive le dipendenze dei moduli usate dal programma
<span class="citerefentry"><span class="refentrytitle">modprobe</span>(8)</span>.</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Nota]" src="images/note.png"/>
</td>
<th align="left">Nota</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Se si hanno problemi di caricamento dei moduli all'avvio o con
<span class="citerefentry"><span class="refentrytitle">modprobe</span>(8)</span>,
"<code class="literal">depmod -a</code>" potrebbe risolverli rigenerando il file
"<code class="literal">modules.dep</code>".</p>
</td>
</tr>
</table>
</div>
<p>Il programma
<span class="citerefentry"><span class="refentrytitle">modinfo</span>(8)</span>
mostra informazioni su un modulo del kernel Linux.</p>
<p>Il programma
<span class="citerefentry"><span class="refentrytitle">lsmod</span>(8)</span>
formatta in un bel modo i contenuti di "<code class="literal">/proc/modules</code>",
mostrando quali moduli del kernel siano attualmente caricati.</p>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Si può identificare l'esatto hardware sul proprio sistema. Vedere <a class="xref" href="ch09.it.html#_hardware_identification" title="9.4.3. Identificazione dell'hardware">Sezione 9.4.3, «Identificazione dell'hardware»</a>.</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Si può configurare l'hardware all'avvio per attivare le funzionalità
dell'hardware desiderate. Vedere <a class="xref" href="ch09.it.html#_hardware_configuration" title="9.4.4. Configurazione dell'hardware">Sezione 9.4.4, «Configurazione dell'hardware»</a>.</p>
</td>
</tr>
</table>
</div>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Tip">
<tr>
<td rowspan="2" align="center" valign="top">
<img alt="[Suggerimento]" src="images/tip.png"/>
</td>
<th align="left">Suggerimento</th>
</tr>
<tr>
<td align="left" valign="top">
<p>Si può probabilmente aggiungere il supporto per il proprio speciale
dispositivo ricompilando il kernel. Vedere <a class="xref" href="ch09.it.html#_the_kernel" title="9.9. Il kernel">Sezione 9.9, «Il kernel»</a>.</p>
</td>
</tr>
</table>
</div>
</div>
</div>
</div>
<div class="navfooter">
<hr/>
<table width="100%" summary="Navigation footer">
<tr>
<td align="left"><a accesskey="p" href="ch02.it.html"><img src="images/prev.png" alt="Indietro"/></a> </td>
<td align="center"> </td>
<td align="right"> <a accesskey="n" href="ch04.it.html"><img src="images/next.png" alt="Avanti"/></a></td>
</tr>
<tr>
<td align="left" valign="top">Capitolo 2. Gestione dei pacchetti in Debian </td>
<td align="center">
<a accesskey="h" href="index.it.html">
<img src="images/home.png" alt="Partenza"/>
</a>
</td>
<td align="right" valign="top"> Capitolo 4. Autenticazione</td>
</tr>
</table>
</div>
</body>
</html>
|