[Linux-cluster] GFS Tunables

[Kevin Anderson]

On Thu, 2008-10-16 at 21:29 +0100, Gordan Bobic wrote:
> Brandon Young wrote:
> 
> > As for LVM snapshotting ... I am under the impression that those 
> > features are unavailable in GFS (and are slated for GFS2?  Which is not 
> > "production ready", yet?)  It has certainly occured to me to try that 
> > feature, if only it were available.  Am I misinformed?  Perhaps I need 
> > some more education on how exactly LVM mirroring will help me.  I am 
> > *attempting* to approximate a traditional backup scheme, atleast on this 
> > particular filesystem.  Am I correct in believing that I could snapshot 
> > a volume (assuming the feature is available) and run a traditional 
> > backup (using, say, rdiff-backup) in a shorter time than I can now, 
> > where I'm running it straight off a live GFS volume?
> 
> You can use CLVM (Cluser aware LVM) and create GFS on top of that 
> volume. You can them use CLVM to take a snapshot of the block device, 
> mount it read-only with lock_nolock and back that up. That should go at 
> non-clustered FS speeds.
> 
We don't have support for cluster snapshots as of yet even though it has
been on the todo list for about 5 years now :(.

Kevin