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Re: [Xen-users] lots of cycles in i/o wait state

To: Miles Fidelman <mfidelman@xxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] lots of cycles in i/o wait state
From: Florian Manschwetus <florianmanschwetus@xxxxxx>
Date: Mon, 07 Jun 2010 08:15:04 +0200
Cc: xen-users <xen-users@xxxxxxxxxxxxxxxxxxx>
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Am 06.06.2010 23:12, schrieb Miles Fidelman:
> Hi Florian,
> Florian Manschwetus wrote:
>> Sounds like hvm without pv-drivers, so a lot of i/o-wait would be normal.
>> Solution =>  enhance yout kernel / drivers.
>> Florian
> Can you provide a few more details on this?  I'm running on a machine
> that doesn't support hardware VM extensions, so I'm pretty sure
> everything is installed with PV drivers.
If your metal has no VM extensions you would need a pv aware kernel, not
ust pv drivers to run anything, so the problem I mentioned is sure out
of the race here. (observed running win2008(normal/r2)x64).

> On the other hand, the VM started as a copy of a system that was running
> directly on bare iron - so maybe there are some kernal modules getting
> loaded somewhere along the line that shouldn't be.
> Any suggestions regarding diagnostics?
Would be worth a look at dom0 activity here, maybe you have an i/o
bottleneck at all.


> Thank you very much,
> Miles Fidelman
> --- original query follows ---

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