From owner-freebsd-hackers Tue Mar 27 0:37:48 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from Awfulhak.org (awfulhak.demon.co.uk [194.222.196.252]) by hub.freebsd.org (Postfix) with ESMTP id 1AE1837B71A; Tue, 27 Mar 2001 00:37:42 -0800 (PST) (envelope-from brian@Awfulhak.org) Received: from hak.lan.Awfulhak.org (root@hak.lan.Awfulhak.org [172.16.0.12]) by Awfulhak.org (8.11.3/8.11.3) with ESMTP id f2R8bST39207; Tue, 27 Mar 2001 09:37:28 +0100 (BST) (envelope-from brian@lan.Awfulhak.org) Received: from hak.lan.Awfulhak.org (brian@localhost [127.0.0.1]) by hak.lan.Awfulhak.org (8.11.3/8.11.3) with ESMTP id f2R8daw48428; Tue, 27 Mar 2001 09:39:36 +0100 (BST) (envelope-from brian@hak.lan.Awfulhak.org) Message-Id: <200103270839.f2R8daw48428@hak.lan.Awfulhak.org> X-Mailer: exmh version 2.3.1 01/18/2001 with nmh-1.0.4 To: Greg Lehey Cc: "Michael C . Wu" , dillon@FreeBSD.ORG, fs@FreeBSD.ORG, hackers@FreeBSD.ORG, brian@Awfulhak.org Subject: Re: Vinum stripe size (was: tuning a VERY heavily (30.0) loaded server) In-Reply-To: Message from Greg Lehey of "Tue, 27 Mar 2001 17:16:53 +0930." <20010327171653.G1161@wantadilla.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 27 Mar 2001 09:39:36 +0100 From: Brian Somers Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > On Tuesday, 20 March 2001 at 11:11:44 -0600, Michael C . Wu wrote: > > [Lengthy email, bear with me please, it is quite interesting. > > This box averages 30.0 load with no problems.] > > > > > > > > Average file size is about 4K. /home/bbsusers* is on a vinum > > stripe'd volume with 3 Ultra160 9G 10000RPM drives on sym0 at stripe > > size 256K, Greg: I know this should be a prime number, > > No, there's no requirement for it to be a prime number. The only > problem is that with 32 MB cylinder groups and a power of two stripe > size and subdisk count, you end up with all the superblocks on one > subdisk, which is a performance issue. Choose the stripe size so that > the superblocks are roughly evenly distributed. A performance issue ? Surely you've misspelt ``reliability'' ? > Greg > -- > Finger grog@lemis.com for PGP public key > See complete headers for address and phone numbers -- Brian Don't _EVER_ lose your sense of humour ! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message