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

Yeah, it may be time to invest in some real drives :-).  It's hard to tell how many disks are being used for the RAID 10 - the information isn't readily available in the user interface for the SAN.  I'm working with the vendor right now, so maybe they can help me out.  Also, I wasn't suggesting the SAN vendor would help with the rsync/startup/shutdown, just that maybe they can tell me if the performance I'm seeing on the SAN is what I should expect or not.  I may have to purchase a chassis of FC disks that run at 10K or 15K RPM.  Current FCATA drives are 7200 RPM.


>>> On 2009/08/27 at 08:30, John Madden <jmadden@xxxxxxxxxxx> wrote:

On Thu, 2009-08-27 at 08:25 -0600, Nick Couchman wrote:
> Let's see...the SAN has two controllers with a 4GB cache in each
> controller.  Each controller has a single 4 x 2Gb FC controller.  Two
> of those ports go to the switch; the other two create redundant loops
> with the disk array (going from the controller to one disk array, then
> to the next disk array, then to the second controler).  The disks are
> FCATA disks, there are 30 active disks (with 2 hot-spares).  The SAN
> does RAIDs across the disks on a per-volume basis, and my e-mail
> volume is using a RAID10 configuration.

FCATA?  Well, that isn't going to help your situation any.  But 30
spindles is a good start.  How many are in your particular RAID 10
group?  It's sounding like 1500 iops might be all this guy can handle
(ATA, maybe 120 iops, RAID 10, so you're using at most 14 of those
disks, that'd give you 1680 iops max -- for reads -- half that for

> tuning parameters for the elevators.  I haven't got around to trying
> something other than XFS, yet - it's going to take a while to sync
> over stuff from the existing FS to an EXT3 or something similar.  I'm
> also contacting the SAN vendor to get their help in the situation.

Shut down, rsync, remount, start up.  I don't think your SAN vendor
could really help here...?


John Madden
Sr UNIX Systems Engineer
Ivy Tech Community College of Indiana

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