From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alberto =?iso-8859-1?q?Trevi=F1o?= Subject: Avoiding I/O bottlenecks between VM's Date: Fri, 19 Sep 2008 11:26:09 -0600 Message-ID: <200809191126.09889.alberto@byu.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "kvm@vger.kernel.org" Return-path: Received: from pto.byu.edu ([128.187.16.44]:10375 "EHLO webmail-int.byu.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750876AbYISRZy (ORCPT ); Fri, 19 Sep 2008 13:25:54 -0400 Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: I am using KVM 69 and kernel 2.6.25.17 to host several VM's in a large server. So far, everything has been great. Except I'm adding a Windows Server VM that will run a SQL Server database. A few times I've noticed that I/O becomes a bottleneck for the VM and Windows VM freezes for a few seconds. Oh well, no biggie. Except, every so often, these I/O bottlenecks start to affect other VM's and they freeze as well for a few seconds. I don't really care of one VM does so much I/O that it freezes itself temporarily. I just don't want I/O bottlenecks on one VM to affect other VM's. My questions are: 1. Is this a problem anyone else has experienced and has it been fixed in a later KVM release? 2. I'm using the CFQ scheduler. Would the deadline scheduler do a better job? 3. Any other suggestions to improve this problem?