From owner-freebsd-scsi Mon Oct 28 10:55:41 1996 Return-Path: owner-freebsd-scsi Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id KAA20205 for freebsd-scsi-outgoing; Mon, 28 Oct 1996 10:55:41 -0800 (PST) Received: from GndRsh.aac.dev.com (GndRsh.aac.dev.com [198.145.92.241]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id KAA20200 for ; Mon, 28 Oct 1996 10:55:37 -0800 (PST) Received: (from rgrimes@localhost) by GndRsh.aac.dev.com (8.7.5/8.7.3) id KAA19511; Mon, 28 Oct 1996 10:55:05 -0800 (PST) From: "Rodney W. Grimes" Message-Id: <199610281855.KAA19511@GndRsh.aac.dev.com> Subject: Re: SCSI harddisk trouble: MEDIUM ERROR In-Reply-To: <199610281416.JAA01140@hda.hda.com> from Peter Dufault at "Oct 28, 96 09:16:39 am" To: dufault@hda.hda.com (Peter Dufault) Date: Mon, 28 Oct 1996 10:55:05 -0800 (PST) Cc: freebsd-scsi@freebsd.org X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > Well put - I should have read your message before responding. However: > > > ... Since we don't do read after write verify operations if > > a data hard error occurs in the block during the write that is undeteced > > during the read there is nothing that AWRE/ARRE can do about it... > > Do think this happens often? Almost certainly all of the reported ``why doesn't ARRE/AWRE'' handle this bad block are instances of this occuring, most likely a write operation that went haywire and undetected. > Are there situations where > "write and verify" support would be worth the probable huge > performance hit? It would be really nice to have a knob to turn it on and off via sysctl, Novell servers have had that knob since the 2.x days, Vax/VMS has had it for as long as I can remember, yes, I do think this would be worth it if we have a knob to twist. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation, Inc. Reliable computers for FreeBSD