Question about limiting KVM cpu usage

Question about limiting KVM cpu usage

[Steve Lorimer]

Hello, all,
    I have what should be a simple question concerning KVM.  Is there a 
way to limit cpu usage for a KVM guest?  In other words, if I am running 
four guest servers and something on one of them begins to use a ton of 
cpu, I don't really want it to slow down all the others.  Is the only 
way to do this by limiting it to one cpu core?  Granted, I would prefer 
that it have access to full computing power if no other guest needs it.  
Thanks for any advice.


Steve Lorimer <slorimer  a t   kmbc.edu

Re: Question about limiting KVM cpu usage

[FinnTux]

2008/9/11 Steve Lorimer <slorimer@kmbc.edu>:
> Hello, all,
>   I have what should be a simple question concerning KVM.  Is there a way to
> limit cpu usage for a KVM guest?  In other words, if I am running four guest
> servers and something on one of them begins to use a ton of cpu, I don't
> really want it to slow down all the others.  Is the only way to do this by
> limiting it to one cpu core?  Granted, I would prefer that it have access to
> full computing power if no other guest needs it.  Thanks for any advice.

You can use standard linux process utilities. Check out nice, ionice
and taskset.

nice to set process priority
ionice to set I/O priority
taskset to set CPU affinity

Re: Question about limiting KVM cpu usage

[Cristi Magherusan]

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On Thu, 2008-09-11 at 20:18 +0300, FinnTux wrote:
> 2008/9/11 Steve Lorimer <slorimer@kmbc.edu>:
> > Hello, all,
> >   I have what should be a simple question concerning KVM.  Is there a way to
> > limit cpu usage for a KVM guest?  In other words, if I am running four guest
> > servers and something on one of them begins to use a ton of cpu, I don't
> > really want it to slow down all the others.  Is the only way to do this by
> > limiting it to one cpu core?  Granted, I would prefer that it have access to
> > full computing power if no other guest needs it.  Thanks for any advice.
> 
> You can use standard linux process utilities. Check out nice, ionice
> and taskset.

I think 'cpulimit' is what you really need.

Cristi
-- 
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247  http://cc.utcluj.ro

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