Re: [Xen-users] High IOWAIT

[Nick Anderson <nick@xxxxxxxxxxxx>]

Maarten Vanraes wrote:
> I must say that we have great problems with extremely high IOWAIT, possibly 
> due to the raid card not being fully hardware raid (allthough we had 
> requested it).
> We even used the tap:aio, but it made no difference.
tap:aio could be part of your problems as well.
Its my understanding that under heavier workloads tap:aio which is still 
file based does not perform as well as a direct disk or lvm.
And on the storage thing, Yes it is kind of a pain that you need many 
disks to get faster speeds, and it seems like all they make is large 
disks anymore. I suppose just look at the extra storage as good backup 
locations :)
How many disk are in your raid set? What hardware raid card did you order?

I would highly recommend a BBU on that raid card. I know for 3ware cards 
specifically there is up to 10% performance increase with BBU present.
--
Nick Anderson <nick@xxxxxxxxxxxx>
http://www.cmdln.org
http://www.anders0n.net

Attachment: nick.vcf
Description: Vcard

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users