On Wed, 2017-06-21 at 16:45 +0800, Qu Wenruo wrote: > Btrfs is always using device ID to build up its device mapping. > And for any multi-device implementation (LVM,mdadam) it's never a > good  > idea to use device path. Isn't it rather the other way round? Using the ID is bad? Don't you remember our discussion about using leaked UUIDs (or accidental collisions) for all kinds of attacks? Cheers, Chris.