On 07/05/2023 20:10, Dave Chinner wrote: > [...] > So how does this work if someone needs to mount 3 copies of the same > filesystem at the same time? > > On XFS, we have the "nouuid" mount option which skips the duplicate > UUID checking done at mount time so that multiple snapshots or > images of the same filesystem can be mounted at the same time. This > means we don't get the same filesystem mounted by accident, but also > allows all the cases we know about where multiple versions of the > filesystem need to be mounted at the same time. > > I know, fs UUIDs are used differently in btrfs vs XFS, but it would > be nice for users if filesystems shared the same interfaces for > doing the same sort of management operations... > > Cheers, > > Dave. Hi Dave, thanks for the information / suggestion. I see no reason for the virtual_fsid fails with 3 or more devices; the idea is that it creates random fsids for the every device in which you mount with the flag, so shouldn't be a problem. Of course renaming to "nouuid" would be completely fine (at least for me) to keep consistency among filesystems; the only question that remains is if we should go with a mount option or the compat_ro flag as strongly suggest by Qu. Cheers, Guilherme
