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

[Robert Nichols]

On 11/14/2011 06:23 PM, Alex Schuster wrote:
> Hi there!
>
> 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.

When you restore, are you restoring the most recent backup?  The "--verify"
option only checks the current mirror.  You'd have to use "--verify-at-time"
to check earlier versions.  I can't imagine why a restore would run into
checksum errors while a verify for that same version would be clean.

If you are trying to restore the most recent backup, you can just copy
files from the mirror.  If you are trying to restore an earlier version,
an act of final desperation would be to edit the (probably compressed)
mirror_metadata file for that timestamp and remove all of the "SHA1Digest"
lines.  The restore will then work, though obviously with no error check.
A "--verify-at-time" for that version would produce a ton of "Cannot find
SHA1 digest ..." warnings.

--
Bob Nichols     "NOSPAM" is really part of my email address.
                Do NOT delete it.