From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: kvm-83 write performance raw Date: Mon, 02 Mar 2009 14:35:00 -0600 Message-ID: <49AC42F4.3030101@codemonkey.ws> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Mailing Lists To: AelMalinka@gmail.com Return-path: Received: from qw-out-2122.google.com ([74.125.92.25]:48358 "EHLO qw-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755292AbZCBUfF (ORCPT ); Mon, 2 Mar 2009 15:35:05 -0500 Received: by qw-out-2122.google.com with SMTP id 5so3833618qwi.37 for ; Mon, 02 Mar 2009 12:35:03 -0800 (PST) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Malinka Rellikwodahs wrote: > Host: 2.6.27-gentoo-r8 AMD Opteron 2378 > Guest: Windows XP SP2 > > when running with a raw disk image as a file or a raw disk image on an > lvm vg, I'm getting very low performance on write (5-10 MB/s) however > when using qcow2 format disk image the write speed is much better > (~30MB/s), which is consistant with a very similar setup running > kvm-68. Unfortunately when running the test with qcow2 the system > becomes unresponsive for a brief time during the test. > > kvm -localtime -m 1024 -drive file=,boot=on > > where diskimage is either the qcow2 format image, or the path to the lv > What version of kvm is this? Is it kvm-68? You'll have better luck with something newer than that. Regards, Anthony Liguori > The host is running raid5 and drbd (drive replication software), > however performance on the host is performaning well and avoiding the > drbd layer in the guest does not improve performance, but running on > qcow2 does. > > Any thoughts/suggestions of what could be wrong or what to do to fix this? > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >