From owner-freebsd-current@FreeBSD.ORG Fri Jun 9 19:09:41 2006 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C259F16A418 for ; Fri, 9 Jun 2006 19:09:41 +0000 (UTC) (envelope-from dwhite@gumbysoft.com) Received: from carver.gumbysoft.com (carver.gumbysoft.com [66.220.23.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 93C2143D70 for ; Fri, 9 Jun 2006 19:09:41 +0000 (GMT) (envelope-from dwhite@gumbysoft.com) Received: by carver.gumbysoft.com (Postfix, from userid 1000) id 3E27E72DA2; Fri, 9 Jun 2006 12:08:15 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by carver.gumbysoft.com (Postfix) with ESMTP id 3BD8A72D9F; Fri, 9 Jun 2006 12:08:15 -0700 (PDT) Date: Fri, 9 Jun 2006 12:08:15 -0700 (PDT) From: Doug White To: Chris Hedley In-Reply-To: <20060609163735.D829@aga.cbhnet> Message-ID: <20060609120159.I60598@carver.gumbysoft.com> References: <20060609163735.D829@aga.cbhnet> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: current@freebsd.org Subject: Re: aac0: COMMAND 0xffffffffxxxxxxxx TIMEOUT AFTER xx SECONDS X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Jun 2006 19:09:41 -0000 On Fri, 9 Jun 2006, Chris Hedley wrote: > I've been receiving this message quite a lot lately if I put my Adaptec > 2410SA aac controller under really heavy load. A quick look at the archives > suggests that it used to be a problem a couple of years ago, but was > apparently fixed. Personally I've had no bother with it until a few months > ago when I upgraded my version of -CURRENT, at which point it started > misbehaving. I assume you've checked cabling and termination? Frequently, driver updates can improve performance which means less tolerance for marginal configurations. > I'm also wondering if I might not be better off actually replacing the card > with something better, or at least something better suited to FreeBSD: with > the discs' and controller's write-caching turned off, the 2410SA is s-l-o-w, > about 6MB/s for contiguous writes to an array (either RAID-5 or RAID-10) > (benchmarked using the admittedly somewhat crude "dd various block sizes > to/from a /dev entry" technique), although reads are acceptable at > ~50-60MB/s, if not especially earth-shattering. Any suggestions (for > something inexpensive! If money were no object I'd've gone for a SCSI-only > system), or might I just as well stick with the 2410SA? 6MB/s sounds like you aren't getting any help from the card's write cache; its having to do stripe reads to recalculate parity instead of doing full stripe writes. Many cards disable write-back cache if the battery module isn't present -- make sure you have one and its working. /dev accesses also use physio so you don't get any benefit from write combining in the filesystem layer. Also, in general, hardware RAID beats PCI RAID, hands down. -- Doug White | FreeBSD: The Power to Serve dwhite@gumbysoft.com | www.FreeBSD.org