Re: [rdiff-backup-users] Error "Unable to compare" BUT THEN"Nochanges found. Directory matches." What?

[Steven Willoughby]

On 08/12/2010 03:55 PM, Robinson, Eric wrote:
> You mean the rdiff-backup version? It's 1.2.8 on both servers. But does
> it to an in-place comparison? If I understand the man page correctly, it
> first copies the data from the dest to the source and then compares it
> there?

I'm also running 1.2.8 on my hosts, I'm not sure why you are getting 
warnings with --compare-hash.  In any case, I think you misunderstood 
the man page (if you're talking about what it says for --compare-hash). 
 It will re-read all of the data on the source side in order to compute 
a hash and then compare that hash with what is stored in the backup 
metadata.  I haven't seen the code in question or ever used this option 
before yesterday so I'm not 100% sure that the data won't be transferred 
over the network, but it shouldn't be.

> I definitely care about more than just the most recent backup. I need to
> be able to restore from prevous days, weeks, and months, which was the
> whole point of using rdiff-backup in the first place. But I can
> understand using the most recent backup as a benchmark for testing the
> backup quality.

If you're testing backup quality then you should use the 
--verify-at-time option instead of the --compare option.  I have been 
using it in production (debian stable, rdiff-backup 1.2.5) for a long 
time.  I think the intention of the --compare option is to see what 
files have changed on the source, not to verify old backups.

Steven