Re: KVM performance vs. Xen

[Andrew Theurer <habanero@linux.vnet.ibm.com>]

Nakajima, Jun wrote:
> On 4/29/2009 7:41:50 AM, Andrew Theurer wrote:
>   
>> I wanted to share some performance data for KVM and Xen.  I thought it
>> would be interesting to share some performance results especially
>> compared to Xen, using a more complex situation like heterogeneous
>> server consolidation.
>>
>> The Workload:
>> The workload is one that simulates a consolidation of servers on to a
>> single host.  There are 3 server types: web, imap, and app (j2ee).  In
>> addition, there are other "helper" servers which are also
>> consolidated: a db server, which helps out with the app server, and an
>> nfs server, which helps out with the web server (a portion of the docroot is nfs mounted).
>> There is also one other server that is simply idle.  All 6 servers
>> make up one set.  The first 3 server types are sent requests, which in
>> turn may send requests to the db and nfs helper servers.  The request
>> rate is throttled to produce a fixed amount of work.  In order to
>> increase utilization on the host, more sets of these servers are used.
>> The clients which send requests also have a response time requirement
>> which is monitored.  The following results have passed the response
>> time requirements.
>>
>> The host hardware:
>> A 2 socket, 8 core Nehalem with SMT, and EPT enabled, lots of disks, 4
>> x
>> 1 GB Ethenret
>>
>> The host software:
>> Both Xen and KVM use the same host Linux OS, SLES11.  KVM uses the
>> 2.6.27.19-5-default kernel and Xen uses the 2.6.27.19-5-xen kernel.  I
>> have tried 2.6.29 for KVM, but results are actually worse.  KVM
>> modules are rebuilt with kvm-85.  Qemu is also from kvm-85.  Xen
>> version is "3.3.1_18546_12-3.1".
>>
>> The guest software:
>> All guests are RedHat 5.3.  The same disk images are used but
>> different kernels. Xen uses the RedHat Xen kernel and KVM uses 2.6.29
>> with all paravirt build options enabled.  Both use PV I/O drivers.  Software used:
>> Apache, PHP, Java, Glassfish, Postgresql, and Dovecot.
>>
>>     
>
> Just for clarification. So are you using PV (Xen) Linux on Xen, not HVM? Is that 32-bit or 64-bit?
>   
PV, 64-bit.

-Andrew