From owner-freebsd-isp@FreeBSD.ORG Mon Oct 27 18:02:53 2003 Return-Path: Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7CF9C16A4CE for ; Mon, 27 Oct 2003 18:02:53 -0800 (PST) Received: from areandor.numenor.net (areandor.numenor.net [69.55.237.153]) by mx1.FreeBSD.org (Postfix) with ESMTP id E54A243FE5 for ; Mon, 27 Oct 2003 18:02:52 -0800 (PST) (envelope-from mentat@numenor.net) Received: from mentat by areandor.numenor.net with local (Exim 3.36 #1) id 1AEJBv-000KIv-00; Mon, 27 Oct 2003 18:02:39 -0800 Date: Mon, 27 Oct 2003 18:02:39 -0800 From: Nathan Kay To: "Eric W. Bates" Message-ID: <20031028020239.GA74323@numenor.net> References: <0ac901c393ea$4bc1ac80$68c311cc@fortiva> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0ac901c393ea$4bc1ac80$68c311cc@fortiva> cc: freebsd-isp@freebsd.org Subject: Re: consequences of migrating to maildir storage system X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Oct 2003 02:02:53 -0000 On Thu, Oct 16, 2003 at 09:34:56AM -0400, Eric W. Bates wrote: > Anyone have unfortunate experiences as a consequence of converting > mail storage from flat file (mbox) to maildir? I'm concerned that the > increase in the number of files might cause problems with replication > (we use rsync), backup or even just running out of inodes. The two issues that I've seen with maildir and large mail environments are both file system related. First, watch your inodes, you may find yourself eating them up quickly. As noted already in the thread, newfs options can solve this issue. The other thing to watch out for, depending on your userbase and usage patterns is lost space from files smaller that your block size. That is to say, if your file system block size is 16k, and most of the email messages are 1k, that's 15k per message (on average) that you've lost, unless the file system is doing things to avoid it. Also, if you're using a network file system that pre-fetches file and directory attributes, you may eventually want to look into what your cache miss rates are for that. Depending on the usage patterns, pre-fetching file and directory attributes for network mounted file systems that are storing maildirs can be either a very good thing, or a very bad thing. Depends on your cache miss rates. -- Nathan Kay Numenorean Networks http://www.numenor.net PGP Public Key: http://www.numenor.net/~mentat/pgp.asc "Unix is like a Vorlon: It's incredibly powerful, gives terse, cryptic answers, and has a lot of things going on in the background."