Re: [Duplicity-talk] silent data corruption with checkpoint/restore

[edgar . soldin]

Does a verify run detect them? .. ede


On 03.08.2010 04:16, Liraz Siri wrote:
> I've found a much more serious bug with checkpoint/restore that leads to
> silent data corruption. I'm using duplicity 0.6.09 installed
> on a 32-bit Ubuntu system, backing up to the local filesystem.
>
> I discovered this by running two full backups with the same parameters.
>
> duplicity --archive-dir /var/cache/duplicity --volsize 10
> --include-filelist /tmp/filelist --exclude '**' /
> file:///var/tmp/duplicity
>
> The first backup I allowed to complete without interruption.
>
> The second backup I repeatedly stopped/resumed after the first volume
> had been created.
>
> I then restored the backups to /tmp/restore.broken and /tmp/restore and
> compared them as follows:
>
>         cd /tmp/restore
>         find |xargs stat -c "%n %U %G %A %s">  statlist
>
>         cd /tmp/restore.broken
>         find |xargs stat -c "%n %U %G %A %s">  statlist
>
>         cd ../
>         diff -u /tmp/restore/{statlist,statlist.broken}
>
> I discovered what looks like one corrupt file for each time I
> CTRL-C/resumed the backup. I'm pretty sure these are the files duplicity
> resumed from.
>
> I would recommend that until this is fixed nobody use the
> checkpoint/restore feature but unfortunately there doesn't seem to be
> any way to disable it (in duplicity 0.6).
>
> If you've already used checkpoint/restore in a version of duplicity that
> has this bug it would be wise to recreate your backups immediately. Just
> make sure the backup completes.
>
> Cheers,
> Liraz
>
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