RE: [Xen-devel] Re: poor domU VBD performance.

To:	"Andrew Theurer" <habanero@xxxxxxxxxx>, "Peter Bier" <peter_bier@xxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	RE: [Xen-devel] Re: poor domU VBD performance.
From:	"Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>
Date:	Tue, 29 Mar 2005 09:13:27 +0100
Delivery-date:	Tue, 29 Mar 2005 08:13:39 +0000
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Thread-topic:	[Xen-devel] Re: poor domU VBD performance.

> It looks like there might be a problem were we are not 
> getting a timely 
> response back from dom0 VBD driver that the io request is 
> complete, which 
> limits the number of outstanding requests to a level which 
> cannot keep the 
> disk utilized well.  If you drive enough IO outstanding 
> requests (which can 
> be done with either o-direct with large request or a much 
> larger readahead 
> setting with buffered IO), it's not an issue. 

Andrew, please could you try this with a 2.4 dom0, 2.6 domU.
Thanks,
Ian

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