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-devel

Re: [Xen-devel] A Performance Comparison of Hypervisors

To: Nicholas Lee <emptysands@xxxxxxxxx>
Subject: Re: [Xen-devel] A Performance Comparison of Hypervisors
From: Anthony Liguori <aliguori@xxxxxxxxxxxxxxxxxx>
Date: Sat, 03 Feb 2007 10:14:56 -0600
Cc: Xen development list <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Tue, 06 Feb 2007 01:37:29 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <2b6116b30702030134j762eed51ud48dc9567d904e97@xxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <2b6116b30702030134j762eed51ud48dc9567d904e97@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 1.5.0.9 (X11/20070103)
Nicholas Lee wrote:
Obviously not a very fair comparison [1]. I can't see how this was done well at all.

I wonder why you say this. I thought the benchmark was done very well. What we need is more benchmarking, not less. Unfortunately, VMware makes publishing benchmarks difficult as you have to get their approval.

This benchmark tells us something, the question is what does it tell us. Let's take a look at the benchmarks they choose. SPECcpu2000 and SPECjbb2005 are two favorite benchmarks of virtualization vendors. They are favorites because everyone does well under them :-) Both aren't sensitive to PTE update or context switch latency and don't involve IO very much. Even QEMU wouldn't look so bad against these :-)

I'm not familiar with Passmark, but it looks like it's mostly CPU bound. For all of these virtualization friendly workloads, Xen does pretty well compared to VMware. For some of the Passmark bits, Xen actually inches out VMware. Considering we're Open Source, they really have no excuse to ever be slower than we are :-)

The compile workload was, IMHO, the most serious of the benchmarks. VMware walloped us on that one. I suspect that's a some shadow paging overhead and perhaps some disk IO overhead.

The Netperf results are a tad silly. They choose Win2k3 for the guest OS. They installed a paravirtual network driver in their guest (vmxnet). However, since no PV network driver is available for Windows for Xen 3.0.3, they used emulated IO[1]. Of course performance is going to suck.

I would have rather seen the benchmarks done with a Linux guest using the PV drivers that are in the tree.

The only embarrassing part is that they weren't able to boot a Win2k3 guest with SMP support. I suspect we need either more QA for HVM or a better statement of supported guest confirmations.

Regards,

Anthony Liguori

[1] The PV drivers that come in XenEnterprise are, AFAIK, only for XenEnterprise.

VMWare are a bit silly to release stuff like this, just lowers the whole game.


[1] http://www.vmware.com/vmtn/resources/711
------------------------------------------------------------------------

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


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