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[Xen-users] Re: Runing dbench on virtual domains, incorrect results!

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Subject: [Xen-users] Re: Runing dbench on virtual domains, incorrect results!
From: Parissa Heidari <parisa.heidari@xxxxxxxxxx>
Date: Mon, 28 May 2007 23:36:53 -0400
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I found out my fault. I had a problem with the scheduling algorithm in 
configuration files. Sorry.

On Monday 28 May 2007 12:16, Parissa Heidari wrote:
> Hi,
> I'm running dbench on Xen-dom0, Xen-domU and a real machine to measure the
> performance loss of virtual machines in comparison withe real one.
> The machine has 2 cpus but I have disabled hyperthreading in the bias and
> all my kernels are compiled with SMP disabled. And also its total available
> RAM is 2GB but I have limited available RAM in the kernel command line of
> all machines. SO my real machine has 900MB, dom0 900MB and also my domU has
> 900MB.
> Surprisingly, I see that Xen increases the performance! I have repeated my
> tests many times but the result is the same.
> Here is my results:
> Real machine, unmodified kernel: 237 MB/sec
> Xen-dom0 ( no domU created. dom0 is running lonely) : 261 MB/sec
> Xen-domU (just 1 doU is running besid dom0) : 284 MB/sec
> Seeing better performance on a domU is not so surprising because however
> Dom0 has 900MB, and a domU also 900MB and they have some collaborations to
> access the disk and ..., but I have no idea about what I see on dom0. Is
> this because of bad measurement of time in virtual machines?
> I appreciate your suggestion  or justification,
> Parissa.

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