From: "Bruce Rogers" <BROGERS@novell.com>
To: "Javier Guerra" <javier@guerrag.com>
Cc: <kvm@vger.kernel.org>
Subject: Re: kvm scaling question
Date: Mon, 14 Sep 2009 17:12:52 -0600 [thread overview]
Message-ID: <4AAE79940200004800081113@novprvlin0050.provo.novell.com> (raw)
In-Reply-To: <90eb1dc70909110846k1cd57f08oa67c92644d78c418@mail.gmail.com>
On 9/11/2009 at 9:46 AM, Javier Guerra <javier@guerrag.com> wrote:
> On Fri, Sep 11, 2009 at 10:36 AM, Bruce Rogers <brogers@novell.com> wrote:
>> Also, when I did a simple experiment with vcpu overcommitment, I was
> surprised how quickly performance suffered (just bringing a Linux vm up),
> since I would have assumed the additional vcpus would have been halted the
> vast majority of the time. On a 2 proc box, overcommitment to 8 vcpus in a
> guest (I know this isn't a good usage scenario, but does provide some
> insights) caused the boot time to increase to almost exponential levels. At
> 16 vcpus, it took hours to just reach the gui login prompt.
>
> I'd guess (and hope!) that having many 1- or 2-cpu guests won't kill
> performance as sharply as having a single guest with more vcpus than
> the physical cpus available. have you tested that?
>
> --
> Javier
Yes, but not empirically. I'll certainly be doing that, but wanted to see what perspective there was on the results I was seeing.
And I've gotten the response that explains why overcommitment is performing so poorly in another email.
Bruce
next prev parent reply other threads:[~2009-09-14 23:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-11 15:36 kvm scaling question Bruce Rogers
2009-09-11 15:46 ` Javier Guerra
2009-09-14 23:12 ` Bruce Rogers [this message]
2009-09-11 21:53 ` Marcelo Tosatti
2009-09-11 23:02 ` Andre Przywara
2009-09-14 23:21 ` Bruce Rogers
2009-09-14 23:19 ` Bruce Rogers
2009-09-15 14:10 ` Andrew Theurer
2009-09-12 9:52 ` Proxmox VE 1.4beta1 released Martin Maurer
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