From owner-freebsd-stable@FreeBSD.ORG Thu Oct 15 09:55:27 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3FF421065672 for ; Thu, 15 Oct 2009 09:55:27 +0000 (UTC) (envelope-from freebsd-stable@m.gmane.org) Received: from lo.gmane.org (lo.gmane.org [80.91.229.12]) by mx1.freebsd.org (Postfix) with ESMTP id 82A778FC24 for ; Thu, 15 Oct 2009 09:55:26 +0000 (UTC) Received: from list by lo.gmane.org with local (Exim 4.50) id 1MyN3L-0006g8-Ft for freebsd-stable@freebsd.org; Thu, 15 Oct 2009 11:55:23 +0200 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 15 Oct 2009 11:55:23 +0200 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 15 Oct 2009 11:55:23 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-stable@freebsd.org From: Ivan Voras Date: Thu, 15 Oct 2009 11:55:08 +0200 Lines: 37 Message-ID: References: <9bbcef730910130633w150571a0k461fb4e67a51fb1d@mail.gmail.com> <9bbcef730910131057i71db846et1f0d4aeadef5e302@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Thunderbird 2.0.0.23 (X11/20090928) In-Reply-To: <9bbcef730910131057i71db846et1f0d4aeadef5e302@mail.gmail.com> Sender: news Subject: Re: Extreme console latency during disk IO (8.0-RC1, previous releases also affected according to others) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Oct 2009 09:55:27 -0000 Ivan Voras wrote: > 2009/10/13 Larry Rosenman : > >>>>> note huge packet loss. It looks like it's VM fault or something like it. >>>> It sounds like the VM is failing to execute the guest during certain >>>> types of I/O. A bit of scheduler tracing in the host OS probably wouldn't go >>>> amiss to confirm that the VM really is suspending the guest >>> It's VMWare ESXi underneath, which is *Officially Not Linux* though some >>> ducks may disagree - anyway, I suspect tracing the host in this way is next >>> to impossible without some kind of diamondium-level contract. >>> >> What information do you need? I have a platinum VMWare contract. >> >> What version of ESXi? > > Hi, > > It is ESXi 3.5 - but if the problem is really in ESXi I presume anyone > could reproduce it. My setup is nothing special - Xeon 5405, 8 GB RAM, > SATA drives on ICH9. > > As for what data is needed, it depends on what you can get - from this > discussion thread it looks like it would be enough to verify that disk > IO doesn't leave VM processes waiting (i.e. that disk IO doesn't > interfere with CPU-bound or idle virtual machines). Though now when I > think of it - doesn't Linux ATA driver poll IO in some funky way, > expecting to get lower latency that way? Another data point - the OS in the VM in question hanged today sometime after 5 AM in the following way: * console nonresponsive (also to ctrl-alt-del) * ssh login nonresponsive (timeout) * ping works (!) Judging by the last seen timestamp, the machine should have been in the process of receiving rsync backups - so IO-bound.