From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: XP installation speed: KVM vs Xen Date: Wed, 28 Feb 2007 09:02:21 +0200 Message-ID: <45E528FD.4040604@qumranet.com> References: <1172609205.6539.9.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: aolney-3T5swIX3ET+itgT5ZmApCQ@public.gmane.org Return-path: In-Reply-To: <1172609205.6539.9.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Andrew Olney wrote: > I've been migrating from Xen to KVM for a wide variety of reasons. > > I've noticed, however, that XP installs much much faster with Xen (3.03 > xen-image-xen0-2.6.17-6-generic-xen0 ubuntu) than with KVM (14). > > I haven't clocked it, but for KVM it takes longer than realtime (by the > XP install clock) and with Xen it takes less than realtime. > > I assume that this is all file I/O related, which raises the question: > what file system setup optimizes KVM I/O, e.g. qcow vs. raw? > The best file format is not a file, but a raw partition or lvm volume. Second best is a raw partition that has been prewritten using dd. Pinning kvm to a cpu may help; try prefixing the command with 'taskset 1'. Please report you experiences, especially about the last hack, as it indicate a serious problem. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV