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] Difference performances between HVM and PV guest in har

To: xen-users list <xen-users@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] Difference performances between HVM and PV guest in hard disc reading
From: Heli <helicoterus-elih@xxxxxxxx>
Date: Mon, 25 May 2009 20:50:58 +0200
Delivery-date: Mon, 25 May 2009 11:51:32 -0700
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.it; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=1fV05LnYknEs2dTVIubD3nRhCHNV5YvYE6+WsX4z18iSeCjSliOI+J8D7GpxBzvW5JTTnGXSCQe4K48XFdSdOaRmAcPgFk22XfJat5yo0kR3NYkAflLOG32ddtdO4+N1sX07AFLNbNbjINnGVtqF1RxVnFcrX2FZGcIRicNeGCA= ;
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <7207d96f0905241536h5d1e9063ke6737b0dc2a4c2e4@xxxxxxxxxxxxxx>
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/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <51147.49632.qm@xxxxxxxxxxxxxxxxxxxxxxxxxxx> <7207d96f0905241536h5d1e9063ke6737b0dc2a4c2e4@xxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird (Windows/20090302)
Fajar A. Nugraha ha scritto:
On Sun, May 24, 2009 at 7:25 PM,  <helicoterus-elih@xxxxxxxx> wrote:
I perform some tests to get hard disc performance differences between HVM domU 
and a paravirtualized one (both Debian Lenny).

first of all, make sure you do NOT use file:/ in domU config. At least
use tap:aio:

I used hdparm ( option -t and -T) to test cache of disc and disc sequential 
Syntax is:
hdparm -t|-T /dev/hda1

hdparm -t for hvm returns about 30 MB/sec, wheras hdparm -t for PV return about 
180 MB/sec.

This is normal. HVM by default should have MUCH lower disk throughput.
That's why HVM domUs need PV drivers for both Linux (included by
default on RHEL/Centos 5.3, not available yet for newer kernels) and
Windows (like GPLPV).
Where I can find this drivers for debian?
I would like to test a debian HVM virtual machine with these "magic" drivers.
I only saw windows ones.

Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com
Xen-users mailing list