From owner-freebsd-fs Thu Dec 14 15:35:19 2000 From owner-freebsd-fs@FreeBSD.ORG Thu Dec 14 15:35:17 2000 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from smtp02.primenet.com (smtp02.primenet.com [206.165.6.132]) by hub.freebsd.org (Postfix) with ESMTP id 45CBC37B402 for ; Thu, 14 Dec 2000 15:35:17 -0800 (PST) Received: (from daemon@localhost) by smtp02.primenet.com (8.9.3/8.9.3) id QAA10094; Thu, 14 Dec 2000 16:30:26 -0700 (MST) Received: from usr08.primenet.com(206.165.6.208) via SMTP by smtp02.primenet.com, id smtpdAAAlkaaFt; Thu Dec 14 16:30:08 2000 Received: (from tlambert@localhost) by usr08.primenet.com (8.8.5/8.8.5) id QAA15873; Thu, 14 Dec 2000 16:34:48 -0700 (MST) From: Terry Lambert Message-Id: <200012142334.QAA15873@usr08.primenet.com> Subject: Re: Filesystem tuning (minimize seeks) To: bright@wintelcom.net (Alfred Perlstein) Date: Thu, 14 Dec 2000 23:34:48 +0000 (GMT) Cc: tlambert@primenet.com (Terry Lambert), henrich@sigbus.com (Charles Henrich), freebsd-fs@FreeBSD.ORG In-Reply-To: <20001214150353.J4589@fw.wintelcom.net> from "Alfred Perlstein" at Dec 14, 2000 03:03:54 PM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: tlambert@usr08.primenet.com Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > The NFS protocol is defined as not returning success unless the > > write has been committed to stable storage. In FreeBSD, this > > tends to serialize NFS I/O from a single client, and between > > multiple clients in excess of the number of nfsiod's you are > > running. > > This is untrue for NFSv3, that's why there are write and commit > RPCs. By using write ahead then delaying the commit you can > increase performance by only stalling out a single nfsiod to > sync out a large section of a file. The sync still has to occur before the client returns to the user space program that the write has been successful. This works when you turn a big write into a bunch of little write at the mount write size. For multiple user space write operations, the client still stalls between the writes until after the commit. 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-fs" in the body of the message