[Gluster-users] Horrible Gluster Performance

[Brian Candler]

On Fri, Apr 13, 2012 at 11:25:58AM +0200, Philip wrote:
>    Sometimes the io-latency skyrockets and there is no
>    access possible on the raid for >10 seconds.

Have you checked
http://community.gluster.org/a/linux-kernel-tuning-for-glusterfs/
?

If you have a large amount of RAM and a lot of writes, maybe you're
accumulating large amounts of dirty data which is then being synchronously
flushed.