From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arne Kepp Subject: Re: Poor write- and overall performance Date: Sat, 20 Dec 2008 02:44:23 +0100 Message-ID: <494C4DF7.30106@opengeo.org> References: <49459A51.7040905@opengeo.org> <4945FB64.3040109@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail.smallworld.no ([195.1.161.175]:37198 "EHLO mail.smallworld.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752349AbYLTBoc (ORCPT ); Fri, 19 Dec 2008 20:44:32 -0500 Received: from [10.0.0.22] (147.84-48-122.nextgentel.com [84.48.122.147]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.smallworld.no (Postfix) with ESMTPSA id 356D66C8642 for ; Sat, 20 Dec 2008 02:44:20 +0100 (CET) In-Reply-To: <4945FB64.3040109@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > Arne Kepp wrote: >> Hi, >> >> I'm testing KVM 80 (prepackaged from lfarkas.org) on CentOS 5.2 (both >> guest and host) and comparing against Xen 3.3.0. The only >> modification I've really made is that I've set noatime on both guest >> and host. The guest is running straight from an LVM volume and is >> assigned 4 Gb RAM and 4 virtual CPUs. > > I suggest trying scsi in kvm-81, or setting cache=writeback if you > want to keep using IDE (but be aware of the potential for severe data > loss with the latter option). > Thanks for the tip. I tested with the SCSI driver and 81, unfortunately write performance was approximately the same as before. Keep up the good work, -Arne -- Arne Kepp OpenGeo - http://opengeo.org Expert service straight from the developers