Re: [rdiff-backup-users] Serious data loss using rdiff-backup

[Alistair Popple]

Hi,

I was just wondering if anything is happening with this?  Thanks.

Regards,
Alistair

On Thu, 23 Sep 2004 11:25:10 +1000, Alistair Popple
<address@hidden> wrote:
> > Hmm... so do you think when the symlink to /usr was deleted, /usr was
> > deleted along with it?
> 
> This is probably best explained with an example I used to replicate
> the problem on a test system at home.  Hopefully this is
> understandable (I can clarify anything if it isn't):
> 
> I created the following directory structure in /tmp/rdiff-backup-test/src:
> 
> .
> |-- test1
> |   |-- test1.1
> |   |   |-- a
> |   |   |-- b
> |   |   `-- c
> |   `-- test1.2
> |       |-- d
> |       |-- e
> |       `-- f
> `-- test2
>     |-- test2.1
>     |   `-- test1.1
>     |       |-- g
>     |       |-- h
>     |       `-- i
>     `-- test2.2
>         |-- j
>         |-- k
>         `-- l
> 
> The following steps were then performed:
> * rdiff-backup -v7 address@hidden::/tmp/rdiff-backup-test/src/
> /tmp/rdiff-backup-test/dest/
> * mv /tmp/rdiff-backup-test/src/test2/test2.1
> /tmp/rdiff-backup-test/src/test2/test2.1.old
> * ln -s /tmp/rdiff-backup-test/src/test1
> /tmp/rdiff-backup-test/src/test2/test2.1
> * rdiff-backup -v7 address@hidden::/tmp/rdiff-backup-test/src/
> /tmp/rdiff-backup-test/dest/
> 
> At this point everything should be fine and working as expected.  The
> following directory structure exists in the desination directory:
> 
> |-- rdiff-backup-data
> |   |-- ......................
> |-- test1
> |   |-- test1.1
> |   |   |-- a
> |   |   |-- b
> |   |   `-- c
> |   `-- test1.2
> |       |-- d
> |       |-- e
> |       `-- f
> `-- test2
>     |-- test2.1 -> /tmp/rdiff-backup-test/src/test1/
>     |-- test2.1.old
>     |   `-- test1.1
>     |       |-- g
>     |       |-- h
>     |       `-- i
>     `-- test2.2
>         |-- j
>         |-- k
>         `-- l
> 
> Note the symlink from test2.1 to a file outside the destination path.
> 
> However if the backup fails (eg. it is interrupted halfway through)
> then the desintation directory needs checking:
> * rdiff-backup -v7 --check-desintation /tmp/rdiff-backup-test/dest
> 
> It is at this point the problems begin.  If you check
> /tmp/rdiff-backup-test/src/test1 (a directory outside of the
> destination) you will find that the test1.1 directory has been
> deleted.  This only happens for the directories mentioned in the
> original (non-linked) version of test2.1, which is why test1.2
> remains.  The problem here seems to be that the check-destination-dir
> option follows the symlinks rather than treating them as files.  If
> the link is changed to a relative one then sure enough no directories
> outside of the destination seem to be modified, however after the
> destination check test1.1 is missing from the destination/backup - ie.
> it has _not_ been backed up.  Performing  subsequent backups will also
> not back that information up, even if the relative symlink is removed,
> thus the backups remain incomplete for what I assume is ever more.
>