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] poor harddisk performance HVM domain (Windows 2003 guest

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] poor harddisk performance HVM domain (Windows 2003 guest)
From: Javier Guerra <javier@xxxxxxxxxxx>
Date: Sun, 7 May 2006 11:52:48 -0500
Delivery-date: Sun, 07 May 2006 09:55:23 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <200605071537.59242.joost@xxxxxxxxxxxxx>
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: <200605041625.39239.joost@xxxxxxxxxxxxx> <200605071537.59242.joost@xxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: KMail/1.9.1
On Sunday 07 May 2006 8:37 am, Joost van den Broek wrote:
> It even gets worse when installing and using Ubuntu HVM, can't enable DMA
> for the QEMU harddisk, resulting in a very slow +-3.5MB/s read. Isn't there
> any way to resolve this?

qemu's HD emulation is very primitive; no DMA, no LBA48.  but it shouldn't be 
such slow, since the real device (in dom0) does have DMA.  of course, the 
best solution is still in the future, when a HVM domain would accept special 
paravirtualized drivers for HD and network.  those will be needed to get 
better performance for windows.

PD, the newest version of qemu does have both DMA and LBA48, but i think 
nobody has bothered porting it to Xen

-- 
Javier

Attachment: pgp2nXzHLfRPp.pgp
Description: PGP signature

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