[Linux-cluster] nolock and dlm nodes in the same cluster

[Bernard Chew]

Hi Sven,

Not sure if it helps; have you tried to export GFS2 as NFS read-only
and mount it in the backup node for backups?

Regards,
Bernard

> On Fri, Jan 14, 2011 at 5:39 AM, Sven Karlsson <karlesven at gmail.com> wrote:
> G'day,
>
> We have a GFS2 cluster on a fibre-SAN with three machines, of which
> one machine is used for remote backups.
>
> The cluster contains a lot of small files, and the backup operation
> takes about a day to complete. When investigating, we found that the
> major performance bottleneck was the file locking operations. We
> stopped the cluster and mounted the backup-node with the lock_nolock
> option, and now backups were blazing.
>
> After careful consideration of the nolock-warning in the documentation
> (i.e. corruption and kernel panics may happen), I wonder if that is
> still the case if spectator mode is used?
>
> Or is there some other options that are available? The files will not
> be modified by the other nodes during this time, so there is no actual
> need for file-level locking... but perhaps the DLM is also handling
> meta-data and other locking that is necessary and it is therefore not
> possible to use nolock?
>
> /Sven
>
> --
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster
>