From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Karsten M. Self" Subject: Re: domU NFS performance Date: Mon, 29 Aug 2005 12:16:05 -0700 Message-ID: <43135EF5.8070604@xensource.com> References: <2b6116b305082902295d8c903b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <2b6116b305082902295d8c903b@mail.gmail.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel List-Id: xen-devel@lists.xenproject.org Nicholas Lee wrote: >I've written up a short review of the past few months experimenting >with a Xen based Ubuntu NX thin client server. > >http://stateless.geek.nz/2005/08/29/xen-disk-performance/ > >I'm wondering if other people have experience similar stalling issues >with NFS services in a domU. Is it a known issue? > > Nicholas: I'm with Keir, this shouldn't be happening. I'm with XenSource QA, this looks like an interesting situation. Could you provide us with some additional information (some you've already given). There's a script I've written to gather system information called, oddly enough, system-info. Find a copy at http://linuxmafia.com/~karsten/Download/system-info (I'll see about getting this to the Cambridge site, we're looking at using this here). Try running that on both the DomU and physical system as this will give us an idea of your system state as well. You might also want to: - Provide specific NFS version info. - Check system logs on client and server for any possible related info. - Monitor traffic (tcpdump, ethereal, iptraf) to determine if latency is visible at network / protocol level. - Provide specific network hardware specs. We *are* seeing issues with specific cards, and have seen some quirks with hub/switch configurations. My own experience with mutt is that it can be notoriously laggy particularly dealing with large or frequently updated mailboxes. It may not be the best general purpose network performance test tool. Perhaps netperf (packaged for Debian) would be more useful. As Kier indicates, we're largely dogfooding internally with services run via Xen DomUs, so this is a bit of a puzzler. Cheers. -- Karsten M. Self XenSource, Inc. 2300 Geng Road #250 +1 650.798.5900 x259 Palo Alto, CA 94303 +1 650.493.1579 fax