From owner-freebsd-stable Wed Mar 14 3:10:28 2001 Delivered-To: freebsd-stable@freebsd.org Received: from mass.dis.org (mass.dis.org [216.240.45.41]) by hub.freebsd.org (Postfix) with ESMTP id 5FE5C37B719 for ; Wed, 14 Mar 2001 03:10:22 -0800 (PST) (envelope-from msmith@mass.dis.org) Received: from mass.dis.org (localhost [127.0.0.1]) by mass.dis.org (8.11.2/8.11.2) with ESMTP id f2EBDNn04877; Wed, 14 Mar 2001 03:13:24 -0800 (PST) (envelope-from msmith@mass.dis.org) Message-Id: <200103141113.f2EBDNn04877@mass.dis.org> X-Mailer: exmh version 2.1.1 10/15/1999 To: Pete French Cc: stable@FreeBSD.ORG Subject: Re: Disk I/O problem in 4.3-BETA In-reply-to: Your message of "Wed, 14 Mar 2001 11:06:13 GMT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 14 Mar 2001 03:13:23 -0800 From: Mike Smith Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > What doesn't appear to have been mentioned is how exactly do we turn off > > write caching on SCSI drives. From poking around the best I could work > > out was to run 'camcontrol modepage da0 -m 0x08 -e -P 3' and set WCE to > > 0 where 0x08 comes from /usr/share/misc/scsi_modes. > > ...and on a related note, how do you do it on SCSI drives that are > hnaging off the back of a RAID controller, where camcontrol doesnt > seem to be useable (unless I've got the wrong end of the stick completely) Put battery-backed RAM on the RAID controller, and use the RAID controller setup to disable write caching on the drives. Mylex, at least, let you do this. -- ... every activity meets with opposition, everyone who acts has his rivals and unfortunately opponents also. But not because people want to be opponents, rather because the tasks and relationships force people to take different points of view. [Dr. Fritz Todt] V I C T O R Y N O T V E N G E A N C E To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message