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

[Dominic Raferd]

On 15/11/2011 00:23, Alex Schuster wrote:
> I need to restore an old VMware image, but I am getting LOTS of these
> errors:
>
> Error reading /backup/weird/home/wonko/os/vmware/xp/winXPPro-0.log,
> substituting empty file.
> Warning: Hash da39a3ee5e6b4b0d3255bfef95601890afd80709 of winXPPro-0.log
> doesn't match recorded hash db9943d0284382131b553cef380aae99871b0f2e!
>
> Any idea what has happened? rdiff-backup --check-destination-dir --force
> says nothing has to be checked, and option --verify does not find
> errors. The hard drive seems to be okay, no errors in the syslog, and a
> long SMART selftest also does not find any errors. I can restore some
> other directories I tried, but I need the backup of this VMware machine.

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.

Before using rdiff-backup on a VMware vm, my suggestion is to pause or 
suspend or stop the vm (e.g. with vmrun). Alternatively use the VMware 
snapshot facility and backup the snapshot rather than the running vm.

None of this is much help if you have already lost your vm and are 
trying to recover it from backup. You might try recovering older 
versions of the vm (from your rdiff-backup repository), maybe you will 
find a consistent and usable vm there. Also the file you mention is only 
a log file and not critical. The critical files I think are *.vmdk, 
*.vmx and *.nvram.

Regards

Dominic