06.07.2019 23:43, Ulli Horlacher пишет: > On Sat 2019-07-06 (19:57), Nikolay Borisov wrote: > >>> And how can I see whether /test/tmp/xx/ss1 is a snapshot at all? >>> Do all snapshots have a "Parent UUID" and regular subvolumes not? >> >> Indeed, only snapshots have a Parent UUID. > > Not all: > > root@xerus:/test# btrfs subvolume snapshot -r /test /test/ss1 > Create a readonly snapshot of '/test' in '/test/ss1' > > root@xerus:/test# btrfs subvolume show /test/ss1 > /test/ss1 > Name: ss1 > UUID: 02bd07bc-0bab-3442-96be-40790e1ba9be > Parent UUID: - > Received UUID: - > Creation time: 2019-07-06 22:37:37 +0200 > Subvolume ID: 1036 > Generation: 9824 > Gen at creation: 9824 > Parent ID: 5 > Top level ID: 5 > Flags: readonly > Snapshot(s): > > root@xerus:/test# btrfs subvolume show /test > /test is toplevel subvolume > Which is one more reason to not use btrfs top level directly.
