Re: [Xen-users] poor IDE buffered disk reads on dom0

To:	Chris Fanning <christopher.fanning@xxxxxxxxx>
Subject:	Re: [Xen-users] poor IDE buffered disk reads on dom0
From:	Anand <xen.mails@xxxxxxxxx>
Date:	Wed, 25 Jan 2006 20:14:01 +0530
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On 1/25/06, Chris Fanning <christopher.fanning@xxxxxxxxx> wrote:

I have a question about disk access. (IDE in my case)

When I _don't_ boot the xen dom0 kernel and run hdparm -tT
Timing buffered disk reads: 156 MB in 3.03 seconds = 51.44 MB/sec

When I boot xen dom0 and run hdparm -tT
Timing buffered disk reads: 8 MB in 3.22 seconds = 2.48 MB/sec

I'm running this on debian testing and compiling xen3.0.0

When booting dom0 I get those fatal errors of the type "ide_generic
module not found" (i've seen those on other instalations). While
compiling xen from the source I noticed that ide_generic.o (i think)
isn't compiled as a module.

Which kernel are you compiling ? linux-2.6-xen0 / linux-2.6-xen

Ian recommends using the xen kernel since it packs in more drivers, so if you aren't using that, try to compile that and use it.

I'm a bit stuck. Sould I compile ide as a module for dom0?
Or perhaps this isn't even the problem?
Should I forget about IDE and go and buy SATA?

As for SATA, it definately gives you more performance ;)

--

regards,

Anand

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