>
> Following patch adds a nouuid mount option to XFS, which makes it not check
> if the file system uuid is unique on the system. This is useful to mount
> LVM snapshot volumes without having to play games with xfsdb.
>
> -Andi
>
Andi,
Seems like a reasonable idea, but I would extend it in a couple of ways:
1. only allow the nouuid in combination with the ro flag - otherwise you
could get two mounts of the same physical media at the same time, you
will trash the filesystem very quickly. Enforcing this combination will
at least stop people from writing from multiple places, it will still
have the potential for a read only and a read/write copy of the same
filesystem, the readonly copy will get out of date metadata in its
buffers, and possibly crash, so this is definitely a use only if you
really know what you are doing feature.
2. You also need to skip the call to xfs_uuid_unmount() in xfs_unmountfs(),
this will be happily removing the uuid for the original filesystem even
while it is still mounted. This would let you get into the same case as
above and trash the filesystem later on.
This whole thing is based on the theory that recovery does not have to
run on the snapshot, which it should not if I got the snapshot code right.
Steve
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