From owner-freebsd-current@FreeBSD.ORG Sun Mar 9 12:45:40 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2E6EB106566C for ; Sun, 9 Mar 2008 12:45:40 +0000 (UTC) (envelope-from ben@altesco.nl) Received: from altus-escon.com (altesco.xs4all.nl [82.95.106.39]) by mx1.freebsd.org (Postfix) with ESMTP id AEC5F8FC1D for ; Sun, 9 Mar 2008 12:45:39 +0000 (UTC) (envelope-from ben@altesco.nl) Received: from benjoam.stuyts.nl (stuyts.xs4all.nl [82.95.106.42]) by altus-escon.com (8.13.6/8.13.1) with ESMTP id m29CjSTV052875; Sun, 9 Mar 2008 13:45:33 +0100 (CET) (envelope-from ben@altesco.nl) Message-Id: <990680CB-A797-41C2-BDF0-E4968DFBDB94@altesco.nl> From: Ben Stuyts To: duncan.young@pobox.com In-Reply-To: <200803091525.27311.duncan.young@pobox.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v919.2) Date: Sun, 9 Mar 2008 13:45:22 +0100 References: <200803091525.27311.duncan.young@pobox.com> X-Mailer: Apple Mail (2.919.2) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (altus-escon.com [193.78.231.42]); Sun, 09 Mar 2008 13:45:34 +0100 (CET) X-Virus-Scanned: ClamAV 0.92.1/6183/Sun Mar 9 11:42:27 2008 on earth.altus-escon.com X-Virus-Status: Clean X-Spam-Status: No, score=-3.8 required=3.5 tests=AWL,BAYES_00 autolearn=ham version=3.2.4 X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on earth.altus-escon.com Cc: freebsd-current@freebsd.org Subject: Re: write cache on usb disks and zfs 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: Sun, 09 Mar 2008 12:45:40 -0000 Hi, On 9 Mar 2008, at 06:25, Duncan Young wrote: > I am trying to use the USB drives for backup and would like to use > zfs on > them, but the problem I have is with the cache disabled, I get lots of > > kernel: (da2:umass-sim0:0:0:0): SYNCHRONIZE CACHE. CDB: 35 0 0 0 0 0 > 0 0 0 0 > kernel: (da2:umass-sim0:0:0:0): CAM Status: SCSI Status Error > kernel: (da2:umass-sim0:0:0:0): SCSI Status: Check Condition > kernel: (da2:umass-sim0:0:0:0): ILLEGAL REQUEST asc:20,0 > kernel: (da2:umass-sim0:0:0:0): Invalid command operation code > kernel: (da2:umass-sim0:0:0:0): Unretryable error > > errors in /var/log/messages. > > I am assuming that the error messages are harmless, but it would be > nice for > zfs to pay attention and not continually issue the commands. Is > there a way > to do this? I had exactly the same problem (on 7-stable) and have added a quirk for this particular drive to scsi_da.c. In my case the drive became unresponsive for a few seconds, so the transfer rate was very low. Works fine so far with the quirk. I have filed a PR where you can see my changes: http://www.freebsd.org/cgi/query-pr.cgi?pr=121474 Ben