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From: Hermann Himmelbauer <dusty@qwer.tk>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: Disk I/O stuck with KVM - no clue how to solve that
Date: Mon, 8 Nov 2010 15:05:53 +0100	[thread overview]
Message-ID: <201011081505.53540.dusty@qwer.tk> (raw)
In-Reply-To: <AANLkTi=H9PAVOMSK6teziPu8Eu0WN8CYB1qooJgGmvLt@mail.gmail.com>

Am Montag 08 November 2010 07:32:39 schrieb Stefan Hajnoczi:
> If you have the time, you can use perf probes to trace I/O requests in
> the host kernel.  Perhaps completion interrupts are being dropped.
> You may wish to start by tracing requests issued and completed by the
> SATA driver.

Fortunately, some poster from the lkml suggested to set the SATA controller in 
the BIOS from IDE to AHCI, which I did and *maybe* it solved the problem.

There are still some short blocks, but the overall read speed is stable (can 
be seen via iostats/iotop), so only the I/O read distribution between the 
host and KVM has some hiccups, but that seems to be tolerable for now.

But thanks for your idea, if the problem comes back, perf probes may come 
handy!

Best Regards,
Hermann

-- 
hermann@qwer.tk
GPG key ID: 299893C7 (on keyservers)
FP: 0124 2584 8809 EF2A DBF9  4902 64B4 D16B 2998 93C7

      reply	other threads:[~2010-11-08 14:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-05 17:16 Disk I/O stuck with KVM - no clue how to solve that Hermann Himmelbauer
2010-11-06 19:58 ` Stefan Hajnoczi
2010-11-07 16:07   ` Hermann Himmelbauer
2010-11-08  6:32     ` Stefan Hajnoczi
2010-11-08 14:05       ` Hermann Himmelbauer [this message]

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