From owner-freebsd-stable@FreeBSD.ORG Tue Oct 13 10:13:20 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 B0B791065698 for ; Tue, 13 Oct 2009 10:13:20 +0000 (UTC) (envelope-from kris@FreeBSD.org) Received: from kennaway-macbookpro.config (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id D5F018FC17; Tue, 13 Oct 2009 10:13:19 +0000 (UTC) Message-ID: <4AD452CB.7040703@FreeBSD.org> Date: Tue, 13 Oct 2009 11:13:31 +0100 From: Kris Kennaway User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) MIME-Version: 1.0 To: Luigi Rizzo References: <20091012223529.GA77733@onelab2.iet.unipi.it> In-Reply-To: <20091012223529.GA77733@onelab2.iet.unipi.it> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable , Thomas Backman 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: Tue, 13 Oct 2009 10:13:20 -0000 Luigi Rizzo wrote: > On Mon, Oct 12, 2009 at 09:48:42PM +0200, Thomas Backman wrote: >> I'm copying this over from the freebsd-performance list, as I'm >> looking for a few more opinions - not on the problems *I* am having, >> but rather to check whether the problem is universal or not, and if >> not, find a possible common factor. >> In other words: I want to hear about your experiences, *good or bad*! >> >> Here's the original thread (not from the beginning, though): >> http://lists.freebsd.org/pipermail/freebsd-performance/2009-October/003843.html >> >> Long story short, my version: when the disk is stressed hard enough, >> console IO becomes COMPLETELY unbearable. 10+ seconds to switch >> between windows in screen(1), running (or even typing) simple >> commands, etc. This happens both via SSH and the serial console. > > hi, > this issue (not specific to FreeBSD, and not new -- it has been > like this forever) is discussed in some detail here > > http://www.bsdcan.org/2009/schedule/events/122.en.html > > The following code (a bit outdated) can help > > http://lists.freebsd.org/pipermail/freebsd-stable/2009-March/048704.html Are you certain? The reported symptoms sound very unusual. Can you reproduce the problem with the provided instructions yourself? Kris