On 2014-12-01 08:54, MegaBrutal wrote: > 2014-12-01 14:47 GMT+01:00 Roman Mamedov : >> On Mon, 1 Dec 2014 14:38:16 +0100 >> MegaBrutal wrote: >> >>> I've also noticed, a subvolume can just be deleted with an "rm -r", >>> just like an ordinary directory. I'd consider to only allow subvolume >>> deletions with exact "btrfs subvolume delete" commands, and they >> >> This is already the case. 'rm -r' will remove all files in a subvolume, but >> the empty subvolume itself is only deletable via the 'btrfs' command. > > That's great! And there is no way to protect against recursive > deletions (besides setting the subvolume read-only, as you suggested > below), as files are processes individually by "rm". But it's OK, > people should always be very careful with "rm", and it doesn't change > with btrfs. ;) > > >> If you want to make snapshots which can't be removed by ordinary tools, use >> the 'read-only' mode when creating them. > > Yeah, good idea! Anyway, is it possible to change a read-only snapshot > to read-write and vica-versa, or you can only specify read-only while > creating them? > IIRC, there is something that you can do with the properties interface. Personally though, I just make the snapshot RW to start with, and then recursively make it immutable (chattr -r +I), as I never use immutable files for anything else, and it works on any _sane_ filesystem, not just btrfs.