From owner-freebsd-questions Wed Jan 30 17:44: 9 2002 Delivered-To: freebsd-questions@freebsd.org Received: from indigo.quadrant.net (indigo.quadrant.net [207.195.92.9]) by hub.freebsd.org (Postfix) with ESMTP id 19FA837B405 for ; Wed, 30 Jan 2002 17:44:03 -0800 (PST) Received: from git2000 (56K72.quadrant.net [207.195.92.72]) by indigo.quadrant.net (8.9.1/8.9.1) with SMTP id TAA08723; Wed, 30 Jan 2002 19:43:58 -0600 (CST) From: "Scott Gerhardt" To: "Brian T.Schellenberger" Cc: Subject: RE: Softupdates Date: Wed, 30 Jan 2002 19:46:26 -0600 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-reply-to: <20020131011543.10D3A4078@i8k.babbleon.org> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Importance: Normal Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > The write caching issue is more of an IDE-ATA issue. > > As far as I know write caching is not such an issue with > the newer SCSI > > drives that have Tagged Queueing Enabled (see dmesg from > one of my systems > > below). > > > > da0: 160.000MB/s transfers (80.000MHz, offset 63, 16bit), > Tagged Queueing > > Enabled > > > > I could be wrong, so correct me if I am. > > No, you are exactly correct. I think that the ideal would > probably to be > have write caching disabled for ata (IDE) and enabled for SCSI. > > But I do wish that in marginal cases the defaults were more > conservative > myself. I agree with your conservative approach. Soft Updates + write caching on SCSI drives with Tagged Queueing Enabled _should_ be quite safe.... High-end SCSI drives that cost 10x that of IDE should have some "smarts" built into them. The key is to make sure that you are aware of the appropriate firmware upgrades (if any) for the drive models you are running. I know this was an issue with some of the IBM drives. - Scott To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message