Re: Impossible to mount two different copies of the same btrfs

[Hugo Mills <hugo@carfax.org.uk>]

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On Thu, Aug 27, 2015 at 11:53:28AM -0600, Chris Murphy wrote:
> On Thu, Aug 27, 2015 at 11:32 AM, carlo von lynX
> <lynX@time.to.get.psyced.org> wrote:
> > Hi there. Excuse me if I didn't subscribe the list. Just wanted to
> > let you know of this behavior assuming you haven't noticed it yet.
> >
> > When mounting two copies of the same file system from two different
> > hard disks with the intention of syncing the older with the newer
> > one, btrfs behaves differently from ext4: it will mount the first
> > one twice rather than mounting each. I assume it has something to
> > do with all UUIDs being identical, which doesn't disturb ext4 though.
> 
> I'd say any file system that allows mount without warning when two fs
> volumes with the same UUID is a bug. I vastly prefer the XFS behavior
> in this regard which is warn and refusal to mount. You have to use -o
> nouuid to make it happen; and then I guess there's some separate
> handling to still keep the fs instances separate, but I don't know how
> that works at all or how ext4 and Btrfs differ.

   See my other email in this thread. :)

   Hugo.

-- 
Hugo Mills             | You know... I'm sure this code would seem a lot
hugo@... carfax.org.uk | better if I never tried running it.
http://carfax.org.uk/  |
PGP: E2AB1DE4          |

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