From: Gordan Bobic <gordan@bobich.net>
To: kvm@vger.kernel.org
Subject: Re: virtio disk slower than IDE?
Date: Sun, 15 Nov 2009 12:00:09 +0000 [thread overview]
Message-ID: <4AFFED49.9010305@bobich.net> (raw)
In-Reply-To: <4AFFCF18.1080509@redhat.com>
Dor Laor wrote:
> On 11/14/2009 04:23 PM, Gordan Bobic wrote:
>> I just tried paravirtualized virtio block devices, and my tests show
>> that they are approximately 30% slower than emulated IDE devices. I'm
>> guessing this isn't normal. Is this a known issue or am I likely to have
>> mosconfigured something? I'm using 64-bit RHEL/CentOS 5 (both host and
>> guest).
>
> Please try to change the io scheduler on the host to io scheduler, it
> should boost your performance back.
I presume you mean the deadline io scheduler. I tried that (kernel
parameter elevator=deadline) and it made no measurable difference
compared to the cfq scheduler.
Gordan
next prev parent reply other threads:[~2009-11-15 12:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-14 14:23 virtio disk slower than IDE? Gordan Bobic
2009-11-15 9:51 ` Dor Laor
2009-11-15 12:00 ` Gordan Bobic [this message]
2009-11-15 13:15 ` Dor Laor
2009-11-15 22:47 ` Gordan Bobic
2009-11-16 16:40 ` john cooper
2009-11-16 18:11 ` Charles Duffy
2009-11-16 21:09 ` Dor Laor
-- strict thread matches above, loose matches on Subject: below --
2009-11-16 16:53 john cooper
2009-11-17 1:14 ` Gordan Bobic
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