From owner-freebsd-stable Sat Feb 19 2: 7:44 2000 Delivered-To: freebsd-stable@freebsd.org Received: from gndrsh.dnsmgr.net (GndRsh.dnsmgr.net [198.145.92.4]) by hub.freebsd.org (Postfix) with ESMTP id 3B6E237BBD5 for ; Sat, 19 Feb 2000 02:07:40 -0800 (PST) (envelope-from freebsd@gndrsh.dnsmgr.net) Received: (from freebsd@localhost) by gndrsh.dnsmgr.net (8.9.3/8.9.3) id CAA52625; Sat, 19 Feb 2000 02:07:31 -0800 (PST) (envelope-from freebsd) From: "Rodney W. Grimes" Message-Id: <200002191007.CAA52625@gndrsh.dnsmgr.net> Subject: Re: Initial performance testing w/ postmark & softupdates... In-Reply-To: <3.0.3.32.20000219035342.009ce460@207.227.119.2> from "Jeffrey J. Mountin" at "Feb 19, 2000 03:53:42 am" To: jeff-ml@mountin.net (Jeffrey J. Mountin) Date: Sat, 19 Feb 2000 02:07:31 -0800 (PST) Cc: tom@uniserve.com (Tom), stable@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL54 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > At 03:08 PM 2/18/00 -0800, Tom wrote: > >On Fri, 18 Feb 2000, Daniel C. Sobral wrote: > > > >> Tom wrote: > >> > > >> > Not really. You could just use async updates instead of softupdates. > >> > Or an OS that uses async updates. Write caching metadata is always > faster > >> > than re-ordering it intelligently. > >> > >> Softupdates reduces the number of writes needed. It can coalesce writes > >> to the same block. > > > > Async updates are always as fast as softupdates, if not faster. You > >should read the softupdates docs. > > As fast, but not safer. > > Can't recall the entire analogy, but Terry mentioned on -hacker a long time > back something to the effect that softupdates is like having a seatbelt and > an airbag rather than just a seatbelt, as well as a faster car too. Or my own version of this... Async is skydiving with a main, softupdates adds a reserve just in case :-) -- Rod Grimes - KD7CAX @ CN85sl - (RWG25) rgrimes@gndrsh.dnsmgr.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message