From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: Re: Virtio and WinXP (disk drivers) Date: Wed, 25 Feb 2009 14:16:09 +0200 Message-ID: <49A53689.5010501@redhat.com> References: <8d3051340902240144h18568e0etf9c0cef5dbdac1e4@mail.gmail.com> <8d3051340902250403p195af7cfyf19c2beccc1333b5@mail.gmail.com> Reply-To: dlaor@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm@vger.kernel.org To: =?UTF-8?B?QWxww6FyIFTDtnLDtms=?= Return-path: Received: from mx2.redhat.com ([66.187.237.31]:46363 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759644AbZBYMPo (ORCPT ); Wed, 25 Feb 2009 07:15:44 -0500 In-Reply-To: <8d3051340902250403p195af7cfyf19c2beccc1333b5@mail.gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: Alp=C3=A1r T=C3=B6r=C3=B6k wrote: > Hi, > > First of all please allow me to salute the community since this is my > first post. > =20 Congratulations, hoping for the next ones :) > Now my problem. I have been using KVM to conduct tests for various > software on windows, so far it worked out just fine. I use savevm an= d > loadvm to assure that the VM is in the same state for each test. I do > a savevm manually, then start the automatic tests. > > Lately i was trying to optimize parts of my tests, to increase the th= roughput. > > First the network I/O was slow with the default device, and i needed > to copy some files to the VM for each test. The virtio network driver > was fast, but with my bridge networking, on Win XP, after starting th= e > VM with loadvm. This isn't such a big issue since i then started usin= g > e1000 device, and speed increased. I am not sure just how much would > virtio be faster, so the question remains : Doesn't virtio work with > loadvm/savevm, or (most probably) am i doing something wrong? > =20 Indeed virtio performs better than e1000. It should work, please provide host kernel version, kvm version, virtio= =20 net version and windows guest type. Also the cmdline and monitor command will help. > The second issue, even a greather one, is disk access speed in the VM= =2E > Again i have looked at virtio, but it seems that there is no Win > direver. Is that so? What can i do to improove disk access > performance? > > =20 We have beta code for windows pv block. We plan to publish them as soon they will be rock stable. Scsi emulation also exist but might not be=20 100% stable. > The final issue isn't related to performance. With the e1000 device, > accessing or writing files on a samba share from the host failes > saying that the file doesn't exists, (the file exists, i am sure). > This doesn't happen all that often, less than 1% of the time, but it'= s > rather anolying because it influences the tests. it seems to be happe= n > randomly, i caoudm't identify a factor that might be causing it. > > =20 Seems like a samba related bug and not necessarily network bug. > Thank you in advance for your advices. > > -- > Alpar Torok > -- > 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 > =20