/usr/share/man/man8/gnt-os.8.gz is in ganeti 2.15.2-7+deb9u3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man8/../../ganeti/default/root/usr/share/man/man8/gnt-os.8.gz
/usr/share/man/man8/../../ganeti/default/root/usr/share/man/man8/gnt-os.8.gz