[sheepdog-users] Performance Impact of Recovery

[richter at ecos.de]

> 
> We store hash into xattr of the object while the hash is calculated.
Hashes
> are calculated indirectly when 1. 'dog vdi check' 2. recovery. We don't
> calculate hash for normal read/write for better performance.
> 

I did test it and the first recovery has taken about 9h (cluster was in
use). I did a second recovery at the weekend when there is no load on the
cluster and it took about 6:30h, and directly afterwards another one (so
there should be only minimal writes between the two recoveries) and it took
about 7h. There are currently about 160000 objects to recover.

It seems that there is no speed gain by storing the hash values (which I
can't imagine) or the hash values are not stored at all. Is it possible for
me to verify that there are some hash values stored. Is there a simple
command line (e.g. using getfattr)? Maybe there is some configuration error
on my side...

Thanks & Regards

Gerald