On Fri 2017-09-08 (15:10), David Sterba wrote: > On Fri, Sep 08, 2017 at 10:54:46AM +0200, Ulli Horlacher wrote: > > > How can I test if a subvolume is a snapshot? > > The inode number is 256 on a btrfs filesystem: > > if [ stat -f --format=%T $path = btrfs -a stat --format=%i $path = 256 ]; ... > > The directory that's result of snapshotting a subvolume, also called > EMPTY_SUBVOL has inode number 2, but that's not considered a normal > subvolume. This is not true. root@fex:~# mount | grep /mnt/test /dev/sdc1 on /mnt/test type btrfs (rw,relatime,space_cache,subvolid=5,subvol=/) root@fex:~# btrfs subvol show /mnt/test /mnt/test is toplevel subvolume root@fex:~# btrfs subvolume snapshot -r /mnt/test /mnt/test/.snapshot/test Create a readonly snapshot of '/mnt/test' in '/mnt/test/.snapshot/test' root@fex:~# stat --format=%i /mnt/test 256 root@fex:~# stat --format=%i /mnt/test/.snapshot/test 256 No difference: both have inode=256 -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlacher@xxxxxxxxxxxxxxxxxxxx Allmandring 30a Tel: ++49-711-68565868 70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/ REF:<20170908131035.GO31874@xxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
