From owner-freebsd-hackers Thu Dec 14 11:33:33 2000 From owner-freebsd-hackers@FreeBSD.ORG Thu Dec 14 11:33:31 2000 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from hand.dotat.at (sfo-gw.covalent.net [207.44.198.62]) by hub.freebsd.org (Postfix) with ESMTP id 8652D37B402 for ; Thu, 14 Dec 2000 11:33:31 -0800 (PST) Received: from fanf by hand.dotat.at with local (Exim 3.15 #3) id 146e7l-000Nr9-00; Thu, 14 Dec 2000 19:33:05 +0000 Date: Thu, 14 Dec 2000 19:33:05 +0000 From: Tony Finch To: Dag-Erling Smorgrav Cc: Gustavo Vieira Goncalves Coelho Rios , hackers@FreeBSD.ORG Subject: Re: very big mail spool directory Message-ID: <20001214193305.D92196@hand.dotat.at> References: <3A368F8C.1918684F@ifour.com.br> <20001213214404.P71002@hand.dotat.at> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: Organization: Covalent Technologies, Inc Sender: fanf@dotat.at Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Dag-Erling Smorgrav wrote: >Tony Finch writes: >> Why a prime number? All you need is an even spread, and given that >> user IDs are usually allocated sequentially any modulus will do. > >Because a prime number is less likely to cause an imbalance in where >files are actually stored on disk - just like you want an odd (and >preferably prime) stripe size on RAIDs to (amongst other reasons) >avoid having all the superblock backups end up on the same disk. That's another situation in which the collision rate is very low. I still think any number of about the right size will do. Tony. -- f.a.n.finch fanf@covalent.net dot@dotat.at " ``Well, let's go down and find out who's grave it is.'' ``How?'' ``By going down and finding out!'' " To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message