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[Xen-devel] Direct I/O to domU seeing a 30% performance hit

To: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] Direct I/O to domU seeing a 30% performance hit
From: John Byrne <jbyrne@xxxxxxxxxxxxxxxxxxxxxx>
Date: Mon, 06 Nov 2006 21:55:17 -0800
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I was asked to test direct I/O to a PV domU. Since, I had a system with two NICs, I gave one to a domU and one dom0. (Each is running the same kernel: xen 3.0.3 x86_64.)

I'm running netperf from an outside system to the domU and dom0 and I am seeing 30% less throughput for the domU vs dom0.

Is this to be expected? If so, why? If not, does anyone have a guess as to what I might be doing wrong or what the issue might be?

Thanks,

John Byrne






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