Re: [rdiff-backup-users] Error "Unable to compare" BUT THEN "No changes found. Directory matches." What?

[Steven Willoughby]

On 08/10/2010 04:16 PM, Robinson, Eric wrote:
> "It's quiet."
>
> "Yeah, too quiet. Gives me the willies."
>
> "Me, too."
>
> --
> Eric Robinson
>
>
>
> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden
> On Behalf Of Robinson, Eric
> Sent: Saturday, August 07, 2010 8:50 AM
> To: address@hidden
> Subject: [rdiff-backup-users] Error "Unable to compare" BUT THEN "No
> changesfound. Directory matches." What?
>
> I've been using rdiff-backup for a while, but today was the first time I
> tried using the --compare-hash directive.
>
> First I get tons of these messages...
>
>         Warning: Metadata file has no digest for<file>, unable to
> compare.
>
> That's scary enough by itself. But then at the end it says...
>
>         No changes found.  Directory matches archive data.
>
> So if it can't compare, why would it say the directory matches?

I have been running rdiff-backup for a long time with the --verify 
option which does something similar with no issues.  The --compare-hash 
option also seems to be working perfectly for me.  Adding -v6 to your 
command might be enlightening.

> And what is the problem with the hash in the first place?

The hash should be stored in 
$backup_dir/rdiff-backup-data/mirror_metadata.$date.  Try looking at the 
mirror_metadata snapshot previous to the current one (you should be able 
to open it with zless or zcat).  IIRC older versions of rdiff-backup 
(like 1.0) didn't store this hash, so perhaps it is missing.  If that 
was the case then that would explain the warnings and the "No changes 
found." is probably a bug since it didn't find any files that didn't 
match (since all of them were skipped.)

It might work to use the --compare-full option if you haven't been 
storing hashes.

Steven