Xen users - Nov 2010 - Can affect the virtualization the samba performance?

Hi.

i was migrate samba from an old woody server to a virtualized lenny on
a new server.  The virtualized server has four times more resources
than the old server, but some times the performance is really poor.

im discarding all the samba tunning options, but i dont know how to
discard any virtualization issue.  The disk is a img file on the
server, formatted on ext3.

Im evaluating request a dedicated disk to the samba virtual server,
but before i need confirm if the problem is really by disk
performance.

How can i evaluate if the virtualization can have any relation with
the samba performance?

thanks and regards.

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On Thu, Nov 25, 2010 at 6:12 AM, kazabe <kazabe@gmail.com>
wrote:
> Im evaluating request a dedicated disk to the samba virtual server,
> but before i need confirm if the problem is really by disk
> performance.
Run omething like "iostat -mx 3" on the virtual server. If disk
utilization is often close to 100%, then you have the culprit.

Sometimes you don''t necessarily need to have a dedicated disk. You
have to make sure that it''s used optimally. e.g:
- whenever possible, don''t use HVM guest. Use PV guests instead.
- use block device (partition, LVM, whole disk) instead of file-backed image
- when you have to use file-backed image, use tap:aio instead of file:/

-- 
Fajar

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On Wed, Nov 24, 2010 at 3:12 PM, kazabe <kazabe@gmail.com>
wrote:
> Hi.
>
> i was migrate samba from an old woody server to a virtualized lenny on
> a new server.  The virtualized server has four times more resources
> than the old server, but some times the performance is really poor.
>
> im discarding all the samba tunning options, but i dont know how to
> discard any virtualization issue.  The disk is a img file on the
> server, formatted on ext3.
>
> Im evaluating request a dedicated disk to the samba virtual server,
> but before i need confirm if the problem is really by disk
> performance.
>
> How can i evaluate if the virtualization can have any relation with
> the samba performance?
>
> thanks and regards.
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>
Do u have raid on the dom-0? Raid-0,1,5,10?
Have u tune your server?
Have u benchmark your FS? Bonnie, Bonnie++,fio,tiobench,dd,hdparm,iozone,dbench?
This will take a lot of time but will let u know with settings will
give u the best performance for a service la samba.
Good luck!!!

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