Re: Ceph and BackupPC (was: Re: mount: 10.0.6.10:/: can't read superblock)

[Sage Weil <sage@xxxxxxxxxxx>]

On Wed, 6 Jun 2012, Guido Winkelmann wrote:
> Am Dienstag, 5. Juni 2012, 14:33:19 schrieb Martin Wilderoth:
> 
> > I have not done any changes installed at version 0.46 upgraded earlier and
> > have been testing with ceph and ceph-fuse and backuppc.
> 
> BackupPC and Ceph sounds like an interesting combination. Other than this 
> hanging MDS problem, what are your experiences with that?
> 
> I'm asking because BackupPC is the only application I know of that actually 
> makes heavy use of hardlinks. Ceph, as far as I've understood it, supports 
> hardlinks, but works under the assumption that they're a rare and not 
> performance-critical corner case, and does some optimizations that help the 
> more common cases, but would probably hurt if you are using hardlinks a lot.

Right.  There is currently a scalability limit on the number of hard 
links, currently.  Any large set of backuppc data will eat a lot of memory 
on mds.0 and (eventually) case problems.

sage

--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html