From owner-freebsd-stable@FreeBSD.ORG Fri Jan 30 04:43:13 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 BB7E51065672 for ; Fri, 30 Jan 2009 04:43:13 +0000 (UTC) (envelope-from spork@bway.net) Received: from xena.bway.net (xena.bway.net [216.220.96.26]) by mx1.freebsd.org (Postfix) with ESMTP id 643748FC0C for ; Fri, 30 Jan 2009 04:43:13 +0000 (UTC) (envelope-from spork@bway.net) Received: (qmail 33774 invoked by uid 0); 30 Jan 2009 04:43:12 -0000 Received: from unknown (HELO toasty.nat.fasttrackmonkey.com) (spork@96.57.144.66) by smtp.bway.net with (DHE-RSA-AES256-SHA encrypted) SMTP; 30 Jan 2009 04:43:12 -0000 Date: Thu, 29 Jan 2009 23:43:11 -0500 (EST) From: Charles Sprickman X-X-Sender: spork@toasty.nat.fasttrackmonkey.com To: Richard Tector In-Reply-To: <49819672.1090208@thekeelecentre.com> Message-ID: References: <49819672.1090208@thekeelecentre.com> User-Agent: Alpine 2.00 (OSX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-stable@freebsd.org Subject: Re: 7.1, mpt and slow writes 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: Fri, 30 Jan 2009 04:43:14 -0000 On Thu, 29 Jan 2009, Richard Tector wrote: > Charles Sprickman wrote: >> Hello, >> >> I think this needs a few more eyes: >> >> http://lists.freebsd.org/pipermail/freebsd-scsi/2009-January/003782.html >> >> In short, writes are slow, likely do to the write-cache being enabled on >> the controller. The sysctl used in 6.x to turn the cache off don't seem to >> be in 7.x. > > I have two Dell 860's here also running 7.1-REL. > A simple dd on one shows roughly 60MB/s writes to a mirror of 2 320GB disks > on what I'm assuming is the same LSI controller card (SAS5) > > richard@moses:~# cat /boot/loader.conf > hw.mpt.enable_sata_wc=1 > > Seems to work just fine for me. Well, now I'm puzzled. A "sysctl -a" shows no "hw.mpt." tree at all: # sysctl -a|grep hw.mpt # It's a poor test, but: # dd if=/dev/zero of=/jails/foo count=1M 1048576+0 records in 1048576+0 records out 536870912 bytes transferred in 144.830977 secs (3706879 bytes/sec) # dd if=/jails/foo of=/dev/null 1048576+0 records in 1048576+0 records out 536870912 bytes transferred in 4.136582 secs (129786112 bytes/sec) I added the tunable to loader.conf: $ cat /boot/loader.conf hw.mpt.enable_sata_wc=1 And still nothing in the sysctl output (there was on 6.4 on this same hardware, FWIW): $ sysctl -a |grep hw.mpt $ However, performance did improve: # dd if=/dev/zero of=/jails/foo count=16M 16777216+0 records in 16777216+0 records out 8589934592 bytes transferred in 276.332753 secs (31085474 bytes/sec) Any idea what happened to the sysctl? Is there some other method to verify the loader tunable took (other than testing the throughput)? I assume there's still no management tools for these controllers, right? Thanks, Charles > Regards, > > Richard >