82 messages in com.xensource.lists.xen-develRe: RE: [Xen-devel] poor domU VBD per...
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Peter Bier26 Mar 2005 10:14 
Ian Pratt27 Mar 2005 09:41 
peter bier28 Mar 2005 00:48 
peter bier28 Mar 2005 04:44 
Ian Pratt28 Mar 2005 10:54 
Andrew Theurer28 Mar 2005 11:32 
Ian Pratt28 Mar 2005 12:13 
Andrew Theurer28 Mar 2005 12:17 
Andrew Theurer28 Mar 2005 13:48 
Ian Pratt28 Mar 2005 14:16 
Peter Bier28 Mar 2005 15:38 
Andrew Theurer28 Mar 2005 16:27 
Pasi Kärkkäinen28 Mar 2005 22:19 
Ian Pratt29 Mar 2005 00:13 
peter bier29 Mar 2005 00:43 
peter bier29 Mar 2005 03:39 
Kurt Garloff29 Mar 2005 05:33 
Ian Pratt29 Mar 2005 05:38 
Ian Pratt29 Mar 2005 06:19 
B.G. Bruce29 Mar 2005 06:28 
peter bier29 Mar 2005 07:27 
Andrew Theurer29 Mar 2005 10:39.Other
Steven Hand29 Mar 2005 11:13 
Kurt Garloff29 Mar 2005 14:44.diff
Andrew Theurer29 Mar 2005 14:58 
Kurt Garloff29 Mar 2005 15:19 
Andrew Theurer29 Mar 2005 15:26 
Jens Axboe30 Mar 2005 00:53 
Kurt Garloff30 Mar 2005 02:00 
Ian Pratt30 Mar 2005 03:15 
peter bier30 Mar 2005 09:00 
Andrew Theurer30 Mar 2005 10:04 
Jens Axboe30 Mar 2005 23:04 
Jens Axboe30 Mar 2005 23:10 
Keir Fraser31 Mar 2005 00:17 
Jens Axboe31 Mar 2005 00:18 
Philip R Auld31 Mar 2005 06:32 
Kurt Garloff31 Mar 2005 07:34 
Jens Axboe31 Mar 2005 07:39 
Jens Axboe31 Mar 2005 07:41 
Keir Fraser31 Mar 2005 07:49 
Andrew Theurer31 Mar 2005 08:01 
Nivedita Singhvi31 Mar 2005 08:27 
Philip R Auld31 Mar 2005 08:52 
Philip R Auld31 Mar 2005 08:55 
Jens Axboe31 Mar 2005 09:42 
Jens Axboe31 Mar 2005 09:44 
Ian Pratt31 Mar 2005 09:54 
Jens Axboe31 Mar 2005 10:01 
Jens Axboe31 Mar 2005 10:03 
Kurt Garloff31 Mar 2005 10:27 
Philip R Auld31 Mar 2005 10:42 
Keir Fraser31 Mar 2005 10:57 
Keir Fraser31 Mar 2005 11:07 
Keir Fraser31 Mar 2005 11:10 
Jens Axboe31 Mar 2005 11:19 
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Andrew Theurer31 Mar 2005 12:48 
Keir Fraser31 Mar 2005 13:14 
Andrew Theurer31 Mar 2005 13:26 
Ian Pratt31 Mar 2005 13:32 
Nivedita Singhvi31 Mar 2005 13:59 
Andrew Theurer31 Mar 2005 14:13 
Ian Pratt31 Mar 2005 14:36 
Andrew Theurer31 Mar 2005 15:05 
Jens Axboe31 Mar 2005 21:43 
peter bier01 Apr 2005 08:35 
Ian Pratt01 Apr 2005 09:46 
Cédric Schieli01 Apr 2005 13:40 
Ian Pratt01 Apr 2005 15:21 
Cédric Schieli02 Apr 2005 02:36 
Ian Pratt02 Apr 2005 02:56 
Cédric Schieli02 Apr 2005 04:10 
peter bier02 Apr 2005 11:53 
Cédric Schieli03 Apr 2005 08:26 
Ian Pratt03 Apr 2005 09:38 
Cédric Schieli04 Apr 2005 12:13 
Ian Pratt04 Apr 2005 12:36 
Nicholas Lee04 Apr 2005 15:35 
peter bier12 Apr 2005 03:28 
Ian Pratt12 Apr 2005 03:51 
Subject:Re: RE: [Xen-devel] poor domU VBD performance.
From:Kurt Garloff (garl@suse.de)
Date:03/29/2005 05:33:46 AM
List:com.xensource.lists.xen-devel

Hi,

On Mon, Mar 28, 2005 at 09:14:10PM +0100, Ian Pratt wrote:

Is the second disk exactly the same as the first one? I'll try an IO test here on the same disk array with dom0 and domU and see what I get.

I've reproduced the problem and its a real issue.

It only affects reads, and is almost certainly down to how the blkback driver passes requests down to the actual device.

Two points to look at: * Block size (filesystems set this to 4k normally, default it 1k) * Read ahead (you need to do it, otherwise you end up doing tiny requests). You can tune it in sysfs.

Regards,

-- Kurt Garloff, Director SUSE Labs, Novell Inc.