[OpenAFS] disaster recovery

Berthold Cogel cogel@rrz.uni-koeln.de
Thu, 21 Sep 2006 12:28:41 +0200

Dimitris Zilaskos wrote:
>     Thnank you for your tips,
> So far i was able to either restore from the backup or salvage most of 
> the data. However I would like to recover some of the most recent bits 
> that are
> currently lying in lost+found. Is there a way?
> We do have ro copies of all volumes. Unfortunately vos release stopped 
> working about a month ago. Possibly due to the same reasons that 
> resulted to yesterday's disaster.


I had to do this kind of work about two years ago. Take a look at this:


I found it very helpful. It's in German, but perhaps someone can 
translate it for you. With the information provided in the document, the 
tools mentioned in the text, and some cautious looks at the openafs 
header files, I was able to reconstruct some of the fragments in lost+found.

For almost complete volumes structures (small and large vnode index 
files and large vnodes must be available) I can provide you with a 
script that restores the volume directory structure and files to another 
location in 'real' filespace. Filenames are translated to the 'real' 
filenames. For corrupted or missing files, you will get some 
informations and the names, so you can try to find them in the remaining 
fragments. The script also has a 'dry run' mode.

With the additional informations from your old ro volumes, you might be 
able to reconstruct complete volumes. But it's tricky and you will need 
some time.

The script and some of my other tools are a 'first try' and the comments 
are german. I never had the time to rewrite the source. And I'm not a 
very experienced programmer....

Berthold Cogel

Dipl. Chem. Dr. Berthold Cogel                 University of Cologne
E-Mail: cogel@rrz.Uni-Koeln.DE                 ZAIK/RRZK
Tel.:   +49(0)221/470-7873                     Robert-Koch-Str. 10
FAX:    +49(0)221/478-85845                    D-50931 Cologne - Germany