/usr/share/man/man7/ganeti-extstorage-interface.7.gz is in ganeti 2.15.2-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man7/../../ganeti/default/root/usr/share/man/man7/ganeti-extstorage-interface.7.gz