C<if=...> is set at compile time by the configuration option
C<./configure --with-drive-if=...>. In the rare case where you
might need to change this at run time, use C<guestfs_add_drive_with_if>
or C<guestfs_add_drive_ro_with_if>.
C<if=...> is set at compile time by the configuration option
C<./configure --with-drive-if=...>. In the rare case where you
might need to change this at run time, use C<guestfs_add_drive_with_if>
or C<guestfs_add_drive_ro_with_if>.