From owner-freebsd-hackers Wed Mar 4 15:13:52 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA16263 for freebsd-hackers-outgoing; Wed, 4 Mar 1998 15:13:52 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from smtp03.primenet.com (smtp03.primenet.com [206.165.6.133]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA16214 for ; Wed, 4 Mar 1998 15:13:23 -0800 (PST) (envelope-from tlambert@usr01.primenet.com) Received: (from daemon@localhost) by smtp03.primenet.com (8.8.8/8.8.8) id QAA23177; Wed, 4 Mar 1998 16:13:12 -0700 (MST) Received: from usr01.primenet.com(206.165.6.201) via SMTP by smtp03.primenet.com, id smtpd023144; Wed Mar 4 16:13:07 1998 Received: (from tlambert@localhost) by usr01.primenet.com (8.8.5/8.8.5) id QAA17919; Wed, 4 Mar 1998 16:12:53 -0700 (MST) From: Terry Lambert Message-Id: <199803042312.QAA17919@usr01.primenet.com> Subject: Re: Disk write caches To: remy@synx.com (Remy NONNENMACHER) Date: Wed, 4 Mar 1998 23:12:53 +0000 (GMT) Cc: tlambert@primenet.com, hackers@FreeBSD.ORG In-Reply-To: from "Remy NONNENMACHER" at Mar 4, 98 11:29:28 am X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > I would be very interested to see what the benchmarks on a machine > > with soft updates would be with a disk with and without write > > cacheing. > > I tested cache benefits within disks. Write cache disabling lowered the > perfs from 2 to 10 time depending on operations. Did this include soft updates, however? IMO, soft updates is topologically equivalent to moving a write cache from the controller to the kernel. I am *specifically* interested in what an FS mounted with soft updates would do (as I don't personally have the hardware wherewithall to be able to answer the question for myself; my DEC drives don't seem to allow me to turn things off). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message