WARNING - OLD ARCHIVES

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/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

RE: [Xen-users] Exporting a PCI Device

To: "Jan Kalcic" <jandot@xxxxxxxxxxxxxx>
Subject: RE: [Xen-users] Exporting a PCI Device
From: "Joris Dobbelsteen" <Joris@xxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 19 Feb 2008 00:30:42 -0000
Cc: deshantm@xxxxxxxxx, xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Mon, 18 Feb 2008 16:31:25 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
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/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <47B8C482.5050600@xxxxxxxxxxxxxx><1e16a9ed0802171801n591a4949r4ee5e362c2f80f05@xxxxxxxxxxxxxx> <47B965A9.4040300@xxxxxxxxxxxxxx> <E4953B65D9E5054AA6C227B410C56AA9C379@xxxxxxxxxxxxxxxxxxxxxxx> <47BA0A48.9080004@xxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Achyf5jTxt4WQiVtQzGZcbHukC9ffgADhYLQ
Thread-topic: [Xen-users] Exporting a PCI Device
>-----Original Message-----
>From: Jan Kalcic [mailto:jandot@xxxxxxxxxxxxxx] 
>Sent: Monday, 18 February 2008 23:44
>To: Joris Dobbelsteen
>Cc: deshantm@xxxxxxxxx; xen-users@xxxxxxxxxxxxxxxxxxx
>Subject: Re: [Xen-users] Exporting a PCI Device
>
[snip]
>
>I did some test and actually it's quite slow both in reading 
>and in writing. Roughly 50% as Block Device attacched to the domU.
>It reduces complexity but too much is lost in performance.

For some odd reason I'm seeing a similar things on my box with attached
RAID-0 & LVM. The domU only reaches 50%. I don't know the cause, I only
heared comments that it had todo with LVM oddities that RAID seemed to
aggrivate. Nevertheless the dom0 reaches full speed.

Coincidence or a sign of deeper trouble?

My setup is just some standard (cheap) SATA disks, it's a personal
system. It does run Xen 3.1.2, the 2.6.20 kernel on the domU and the
Debian Etch 2.6.18 kernels on the guests. Tests where with Bonnie++
(that's part of debian etch).

To rule out the virtual block device playing tricks I would try to see
what happens with a slower disk on the SAN and even with a local disk
(in the system itself).

- Joris


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