[Box Backup] Box Backup client thinks all symlinks are mount points

Chris Wilson chris at qwirx.com
Wed May 4 23:34:46 BST 2011

Hi Toke,

Sorry for the delay in replying, I was testing the workaround that you 
suggested and I got distracted and forgot all about it.

On Wed, 17 Nov 2010, Toke H??land-J??gensen wrote:

> > Unfortunately, if we worked around it in Box Backup by checking the 
> > device of the symlink target, then we couldn't back up symlinks to any 
> > other filesystem, even though there's no reason not to. I think this 
> > would cause more problems than it would solve.
> Right. I'm sure there is a good reason for it, but I was wondering why 
> boxbackup cares about file system boundaries at all? If told to backup 
> /home, why not just backup /home and mount points be damned? :)

Because we use inode numbers to track file moves, and inode numbers are 
not unique across mount points, so we'd "detect" file moves that hadn't 
really happened.

> Also, when it does have to check for mount points, would it be possible 
> to make this check only for directories? A file can't be a mount point 
> anyway, can it?

I think that's true, so it could be a good workaround. I'll do it.

> > I think this should be reported to the btrfs developers.
> I will pass it on to someone knowledgeable about btrfs. Thanks for your 
> help. :)

Did you get any response from them? I looked for more information about 
this bug in btrfs, thinking that someone else would have noticed it, but 
couldn't find any (that I can remember from two months ago).

Cheers, Chris.
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