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] Very bad network performance between domU and dom0

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] Very bad network performance between domU and dom0
From: Klaus Schmidinger <Klaus.Schmidinger@xxxxxxxxxx>
Date: Mon, 29 Jan 2007 10:20:47 +0100
Delivery-date: Mon, 29 Jan 2007 01:20:44 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <45B9F07C.6010609@xxxxxxxxxx>
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>
Organization: CadSoft Computer GmbH
References: <40726A9415C7FA4E985717142CA98064011E1EDC@xxxxxxxxxxxxxxxxxxxxxxxxxxx> <45B9F07C.6010609@xxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (X11/20060911)
Klaus Schmidinger wrote:
> JHJE (Jan Holst Jensen) wrote:
>>> JHJE (Jan Holst Jensen) wrote:
>>>>> I was able to obtain the xswindrivers.iso file that way and install
>>>>> it into my virtual Windows XP machine. Unfortunately, when 
>>> trying to
>>>>> reboot Windows immediately complained that it could not read from
>>>>> the hard disk, even though I did change the 'vif' and 'disk' config
>>>>> lines to
>>>>> vif = [ 'mac=00:16:3e:00:00:66, bridge=xenbr0' ]
>>>>> disk = [ 'file:/Data/xen/bat-xp.img,hda,w' ]
>>>> I think the PV drivers are SCSI-only, so I guess your disk 
>>> must be "sda"
>>>> instead. If you started out by installing Windows on a 
>>> virtual IDE drive
>>>> you may be hosed :-/.
>>> So I guess this means I should have installed Windows XP in a virtual
>>> SCSI drive. Ok, I changed my 'disk' line to
>>> disk = [ 'file:/Data/xen/bat-xp-scsi.img,ioemu:sda,w', 
>>> 'file:/Data/iso/windows-xp.iso,hdc:cdrom,r' ]
>>> and started the virtual machine on an empty bat-xp-scsi.img file.
>>> The Windows setup comes up, but complains that there is no hard
>>> disk installed in my computer.
>>> Is there anything else I need to configure to have Windows see
>>> an SCSI drive?
>> Hmmm.... This is interesting. The XenExpress help says:
>> "The current version of XenServer supports no more than 3 virtual disks
>> (Disk0-Disk2) for unmodified Windows Xen Virtual Machines. The virtual
>> disks appear to the Windows XenVM as SCSI devices if the paravirualized
>> drivers have been installed, or as IDE devices if the paravirualized
>> drivers have not been installed."
>> and when I look in the Xen config for my Windows VM, the LVM partition
>> is exported as "hda", yet when Windows is booted (with PV drivers) it
>> reports that the C: drive is a Xen PV SCSI drive. Fascinating. I did not
>> look at what Windows thought the hardware was before installing the PV
>> drivers.
>> Can you boot the VM that you installed the PV drivers into if you change
>> the disk spec to be
>>   disk = [ 'file:/Data/xen/bat-xp-scsi.img,sda,w', ...
> I tried both
>   disk = [ 'file:/Data/xen/bat-xp-scsi.img,hda,w' ]
> and
>   disk = [ 'file:/Data/xen/bat-xp-scsi.img,sda,w' ]
> but neither of them worked. With 'hda' Windows brought up the boot
> manager, and when I selected the PV variant it said "Could not read
> from the selected boot disk".
> With 'sda' it didn't even get to the Windows boot manager. The BIOS
> already said "Boot from Hard Disk 0 failed".
>> ? I removed "ioemu", since the PV driver will bypass the ioemu layer -
>> as far as I understand it. Sorry that I can't be more specific, but I
>> have only started using HVM this week so I am learning as well :-).
> Same here ;-)

Does anybody have an idea why my Windows XP guest doesn't boot with
the PV drivers installed, even if I change "hda" to "sda" in the "file"

Actually I wouldn't even need the PV driver for disk access, because
that is working just fine. All I need is better network performance,
so the PV driver for the network adapter would suffice. Is there a
way to install just the PV network driver, without the disk driver?


Xen-users mailing list