CentOS virt - May 2008 - Virtuozzo & GFS

I have just finished deploying two Dell PowerEdge 1950s with CentOS 5.1 and
Virtuozzo 4. GFS is up and running and Virtuozzo is configured for
shared-storage clustering. Everything works adequately but I am wondering if
anyone else has experienced load issues like I am seeing. I have three
VEs/VMs running, two on one node and one on the other node. One of the VEs
on each node are doing very little (one is just idling with apache and mysql
and the other is running rsync every six hours). The other is running
Zimbra. Every so often load will spike on the node running the Zimbra VE to
as high as 2 or 3 then settle down a short while later to around 0.8 or 0.9.
During the spikes the node not running Zimbra will other see an increase
from its idle load of 0.4 or so up to as high as 1.7 as I have seen. I
notice when running top that dlm_send and dlm_recv will jump to the top
fairly frequently when these load spikes occur.
What I am wondering is whether anyone else has experienced these kind of
load scenarios with GFS and what they have done to deal with them? We are
hoping to deploy a bit more densely on this setup so I'd like to make any
performance adjustments I can at this stage.


Thanks,
James Thompson
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James,

----- "James Thompson" <james at ubercart.org>
wrote:
> I have just finished deploying two Dell PowerEdge 1950s with CentOS
> 5.1 and Virtuozzo 4. GFS is up and running and Virtuozzo is configured
> for shared-storage clustering. Everything works adequately but I am
> wondering if anyone else has experienced load issues like I am seeing.
> I have three VEs/VMs running, two on one node and one on the other
> node. One of the VEs on each node are doing very little (one is just
> idling with apache and mysql and the other is running rsync every six
> hours). The other is running Zimbra. Every so often load will spike on
> the node running the Zimbra VE to as high as 2 or 3 then settle down a
> short while later to around 0.8 or 0.9. During the spikes the node not
> running Zimbra will other see an increase from its idle load of 0.4 or
> so up to as high as 1.7 as I have seen. I notice when running top that
> dlm_send and dlm_recv will jump to the top fairly frequently when
> these load spikes occur.
> 
> What I am wondering is whether anyone else has experienced these kind
> of load scenarios with GFS and what they have done to deal with them?
> We are hoping to deploy a bit more densely on this setup so I'd like
> to make any performance adjustments I can at this stage.
> 
> Thanks,
> James Thompson 
A load of 2-3 isn't much at all... so I don't think I'd call that
much of a spike.  I have run OpenVZ at work and on a hobby server.  In both
cases I have about 7 containers... one of them being Zimbra.  The other 6
containers are fairly busy so the two machines see a decent amount of load.  I
am NOT using GFS though.  What is dlm_send and dlm_recv part of?  GFS?

TYL,
-- 
Scott Dowdle
704 Church Street
Belgrade, MT 59714
(406)388-0827 [home]
(406)994-3931 [work]