From owner-freebsd-questions@FreeBSD.ORG Tue Mar 29 18:59:37 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3A50716A4CE for ; Tue, 29 Mar 2005 18:59:37 +0000 (GMT) Received: from relay02.roc.ny.frontiernet.net (relay02.roc.ny.frontiernet.net [66.133.182.165]) by mx1.FreeBSD.org (Postfix) with ESMTP id C686943D39 for ; Tue, 29 Mar 2005 18:59:36 +0000 (GMT) (envelope-from drew@mykitchentable.net) Received: from filter02.roc.ny.frontiernet.net (filter02.roc.ny.frontiernet.net [66.133.183.69])07D1C370475; Tue, 29 Mar 2005 18:59:36 +0000 (UTC) Received: from relay02.roc.ny.frontiernet.net ([66.133.182.165]) [66.133.183.69]) (amavisd-new, port 10024) with LMTP id 31388-02-40; Tue, 29 Mar 2005 18:59:35 +0000 (UTC) Received: from blacklamb.mykitchentable.net (70-97-221-18.dsl2.elk.ca.frontiernet.net [70.97.221.18])0E608370461; Tue, 29 Mar 2005 18:59:32 +0000 (UTC) Received: from [192.168.1.3] (bigdaddy.mykitchentable.net [192.168.1.3]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by blacklamb.mykitchentable.net (Postfix) with ESMTP id 2082C3BF36C; Tue, 29 Mar 2005 10:59:31 -0800 (PST) Message-ID: <4249A594.6000606@mykitchentable.net> Date: Tue, 29 Mar 2005 10:59:32 -0800 From: Drew Tomlinson User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Bob Johnson References: <423A4647.5000709@mykitchentable.net> <200503172323.27821.bob89@bobj.org> In-Reply-To: <200503172323.27821.bob89@bobj.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new-20040701 (2.0) at filter02.roc.ny.frontiernet.net cc: freebsd-questions@freebsd.org Subject: Re: sbp, camcontrol, and Tagged Queuing X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Mar 2005 18:59:37 -0000 On 3/17/2005 8:23 PM Bob Johnson wrote: >On Thursday 17 March 2005 10:08 pm, Drew Tomlinson wrote: > > >>I posted this a while back and am still having the same problem. Can >>anyone offer any insight as to if the sbp man page suggestion about tagged >>queuing is something I should try? Is there any risk of screwing up my >>drives by trying this? >> >Tagged queueing queues up multiple instructions for the drive simultaneously. >The drive then attempts to sort them out and execute them in optimum order. >Some drives that claim to support tagged queueing do not correctly do so, and >don't perform well when it is used (and may lose data). If you set the queue >size to one, as recommended in the passage you reference, then only one >instruction will be issued to the drive at time, and it will behave like a >drive without tagged queueing. It will do no harm to the drive. If the >drive correctly implements tagged queueing, this will slow down the drive, >but if it does not correctly implement it, then this may dramatically speed >up the drive (and make it more stable). I have an external drive that >manages 1.3 MBps transfers with queueing enabled, and 25 MBps transfers when >I set the queue size to one. > >As for whether it will help your specific problem, I don't know, but I can't >see how it would do any harm to test it. > > Using the camcontrol utility, I found these drives were already set to "1" blacklamb# camcontrol tags da2 -v (pass3:sbp0:0:0:0): dev_openings 1 (pass3:sbp0:0:0:0): dev_active 0 (pass3:sbp0:0:0:0): devq_openings 1 (pass3:sbp0:0:0:0): devq_queued 0 (pass3:sbp0:0:0:0): held 0 (pass3:sbp0:0:0:0): mintags 2 (pass3:sbp0:0:0:0): maxtags 255 blacklamb# camcontrol tags da3 -v (pass4:sbp0:0:0:1): dev_openings 1 (pass4:sbp0:0:0:1): dev_active 0 (pass4:sbp0:0:0:1): devq_openings 1 (pass4:sbp0:0:0:1): devq_queued 0 (pass4:sbp0:0:0:1): held 0 (pass4:sbp0:0:0:1): mintags 2 (pass4:sbp0:0:0:1): maxtags 255 Thus setting tagged queuing to "1" had no effect. Thanks again for your explanation. I sure wish I could solve this issue! Thanks, Drew >This issue is not specific to FreeBSD. Any OS that supports tagged queuing >has problems with some drives. > >- Bob > >[...] > > > >>da2 and da3 are two IDE drives in a firewire enclosure. These are also >>the drives that come up "referenced" after restarting. What do these >>errors mean? How can I correct them? Is the following section from the >>sbp man page applicable to my situation? >> >>Some (broken) HDDs don't work well with tagged queuing. If you have prob- >>lems with such drives, try ``camcontrol [device id] tags -N 1'' to dis- >>able tagged queuing. >> >>Thanks for your help! >> >>Drew >> >