Re: [rdiff-backup-users] Hash doesn't match recorded hash

[Dominic Raferd]

I note there was a similar plea last March on this list, you can see it 
here: 
http://www.backupcentral.com/phpBB2/two-way-mirrors-of-external-mailing-lists-3/rdiff-backup-23/restore-fails-110831/. 
Unfortunately there was no published resolution.

I wonder if the problem relates to the temporary folder being used on 
the server or (possibly) on the local machine? Try running the restore 
with --remote-tempdir and --tempdir pointed at locations with bags of space.

Is it only this log file that gives the error message? What about the 
vmdk file?

Dominic

On 15/11/2011 12:27, Alex Schuster wrote:
> Maarten Bezemer writes:
>
> > On Tue, 15 Nov 2011, Dominic Raferd wrote:
> >
> > > On 15/11/2011 00:23, Alex Schuster wrote:
> > > > Warning: Hash da39a3ee5e6b4b0d3255bfef95601890afd80709 of winXPPro-0.log
> > > > doesn't match recorded hash db9943d0284382131b553cef380aae99871b0f2e!
> > > >
> > > > Any idea what has happened?
> > > Vmware files for a running vm may change while being backed up by
> > > rdiff-backup, in which case you don't have a consistent backup. Maybe this is
> > > why you have this inconsistent hash warning.
> > If the contents changed during the rdiff-backup run, it bails out and
> > doesn't save the (inconsistent) increment. So that shouldn't happen.

I didn't know that, but I wonder if it always works like that or whether 
in extreme cases (such as huge vmdk files or corrupted source drive) it 
can break down.

> And I amusing a backup script which takes a LVM snapshot of my /home
> partition before rdiff-backupping it.

Good thinking, but I doubt this guarantees that the vmdk file is consistent.

> Restoring other VMs seems to work, although I did not test many. But I
> cannot restore ANY backup of this special VM I need, I tried about six
> of my twenty backups.
> Well, it would be really nice to be able to restore this VM, but if not,
> I can (and have to) live with that. But I really would like to know why
> this happened, and if I can trust other backups I do.
> I successfully restored this VM in the past already, but that was an
> earlier snapshot I have deleted meanwhile.

Yes I think we would all like an explanation for your problem, and a 
workaround. It could be our problem one day...

Dominic