From owner-freebsd-scsi Mon Oct 12 08:58:09 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA14299 for freebsd-scsi-outgoing; Mon, 12 Oct 1998 08:58:09 -0700 (PDT) (envelope-from owner-freebsd-scsi@FreeBSD.ORG) Received: from pluto.plutotech.com (mail.plutotech.com [206.168.67.137]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA14196; Mon, 12 Oct 1998 08:58:01 -0700 (PDT) (envelope-from gibbs@plutotech.com) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by pluto.plutotech.com (8.8.7/8.8.5) with ESMTP id JAA04320; Mon, 12 Oct 1998 09:57:28 -0600 (MDT) Message-Id: <199810121557.JAA04320@pluto.plutotech.com> X-Mailer: exmh version 2.0.2 2/24/98 To: Don Lewis cc: "Justin T. Gibbs" , Terry Lambert , julian@whistle.com, freebsd-fs@FreeBSD.ORG, freebsd-scsi@FreeBSD.ORG Subject: Re: filesystem safety and SCSI disk write caching In-reply-to: Your message of "Mon, 12 Oct 1998 06:26:05 PDT." <199810121326.GAA09753@salsa.gv.tsc.tdk.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 12 Oct 1998 09:50:42 -0600 From: "Justin T. Gibbs" Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >} 2) Use a drive with non-bogus firmware. Recent Seagate and IBM >} drives should work just fine. I haven't validated any Quantum >} drives in this regard yet. > >But how can tell if the firmware is non-bogus? Ask Terry since he has stated that he 'doesn't have any drives with non-bogus firmware'. Seriously, the major complaint I've heard about firmware has to do with it not properly flushing the cache on a bus reset. I've never seen that failure mode here, and I've done quite a bit of "external bus reset" testing. You'll need sophisticated tools in order to perform these kinds of tests: 1) Find a paper clip 2) Find a ribbon cable that has enough connectors to attach to the device you want to test and the controller with a connector spare. 3) Start lots of writes 4) Ground pin 40 to pin 39 using the paper clip from step 1. 5) Verify data 6) goto 3 -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message