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Re: [Xen-users] xentop --vbds output?

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Subject: Re: [Xen-users] xentop --vbds output?
From: Mark Williamson <mark.williamson@xxxxxxxxxxxx>
Date: Mon, 29 Oct 2007 23:12:47 +0000
Cc: Jared Kuolt <jared@xxxxxxxxxxxxx>
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> What does "OO" mean in the `xentop --vbds` output?

I believe it refers to the number of times that VBD has encountered an "out of 
requests" error which has resulted in IO requests for that VBD being delayed.

The pending request structures are a global resource, so I'd say it's likely 
if you see these going up for one VBD they'll also go up for others.

I guess it's likely to be caused by some combination of (relatively) slow disk 
IO from dom0 and large numbers of requests coming from the VBDs of your 


Dave: Just a question. What use is a unicyle with no seat?  And no pedals!
Mark: To answer a question with a question: What use is a skateboard?
Dave: Skateboards have wheels.
Mark: My wheel has a wheel!

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