This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-users] Xen and I/O Intensive Loads

To: "Pasi Kärkkäinen" <pasik@xxxxxx>
Subject: Re: [Xen-users] Xen and I/O Intensive Loads
From: "Nick Couchman" <Nick.Couchman@xxxxxxxxx>
Date: Wed, 26 Aug 2009 11:57:03 -0600
Cc: XEN Mailing List <xen-users@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Wed, 26 Aug 2009 10:58:16 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20090826173259.GC21121@xxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <4A9507E90200009900017BED@xxxxxxxxxxxxxxxxxxxxx> <20090826173259.GC21121@xxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx

I take that back...iostat in dom0 shows similar results to iostat in domU.  As suggested by another person, I've changed the dom0 elevator to noop and the domU to deadline.  I'm playing with tuning some of the parameters for the deadline scheduler, now.


>>> On 2009/08/26 at 11:32, Pasi Kärkkäinen<pasik@xxxxxx> wrote:

On Wed, Aug 26, 2009 at 10:01:13AM -0600, Nick Couchman wrote:
> Hi, folks,
> The disk volume for the e-mail is on my SAN, and I've attached the FC LUN to my Xen host

Does the SAN LUN perform OK from dom0 without any domUs running?

> I'm running into an issue with high I/O wait on the box (~250%) and large load averages (20-40 for the 1/5/15 minute average).

Do you have iowait on dom0, or only in domU?

Try running "iostat 1" in both dom0 and domU.

Also, have you dedicated a cpu core only for dom0?

> I'm running Xen 3.2.0 on SLES 10 SP2, on a Dell PowerEdge R610 server.  The FC HBA is a QLE2462, dual-channel 4Gb FC card.  Any help, hints, etc., are greatly appreciated!

You could also try updating to SLES11.

-- Pasi

This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR.

Xen-users mailing list