From owner-freebsd-questions@FreeBSD.ORG Tue Jun 22 19:25:41 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C0D5516A4CE for ; Tue, 22 Jun 2004 19:25:41 +0000 (GMT) Received: from scorpion.eng.ufl.edu (scorpion.eng.ufl.edu [128.227.116.10]) by mx1.FreeBSD.org (Postfix) with SMTP id 4C4C643D45 for ; Tue, 22 Jun 2004 19:25:41 +0000 (GMT) (envelope-from bob88@eng.ufl.edu) Received: (qmail 8299 invoked from network); 22 Jun 2004 19:25:24 -0000 Received: from scanner.engnet.ufl.edu (HELO eng.ufl.edu) (128.227.152.221) by scorpion.eng.ufl.edu with SMTP; 22 Jun 2004 19:25:24 -0000 Message-ID: <40D887A3.4060109@eng.ufl.edu> Date: Tue, 22 Jun 2004 15:25:23 -0400 From: Bob Johnson User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.5) Gecko/20031007 X-Accept-Language: en-us, en, eo MIME-Version: 1.0 To: Bill Moran References: <20040621132006.2b1a296f.wmoran@potentialtech.com> <20040621172520.3544d6fe.wmoran@potentialtech.com> <20040621214348.GB63857@happy-idiot-talk.infracaninophile.co.uk> <20040621175626.3e762448.wmoran@potentialtech.com> <40D76DA3.9090809@mac.com> <20040621204111.6e684d45.wmoran@potentialtech.com> <40D79FF9.20308@mac.com> <20040622084726.524bfa39.wmoran@potentialtech.com> <3016.217.162.71.141.1087911989.squirrel@serv04.inetworx.ch> <20040622100825.01f0b258.wmoran@potentialtech.com> In-Reply-To: <20040622100825.01f0b258.wmoran@potentialtech.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: questions@freebsd.org Subject: Re: [OT] Re: What's the best possible email failover solution X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Jun 2004 19:25:42 -0000 Bill Moran wrote: > "David E. Meier" wrote: > >>>Like I said, we'll never know till someone tries it. It looks like >>>Dovecot is going to try it eventually, but it seems like they have >>>other priorities at this time. >> >>"Someone" already stores mails in a database: Oracle (Email Server and >>Collaboration Suite). I set up the Oracle Email Server 5.2 for a company I >>worked for earlier. And to express it nicely: It was a nightmare! Mails >>got stuck and rejected because the system was not capable of writing them >>into the database. Besides, the support for that system was also =0. We >>were probably the only ones daring to run the system ;-) I am glad I am >>running cyrus now. Extremly stable and fast. >> >>That system was not well thought through at all. I don't know how much >>work needs to be done for a database email store, but Oracle wasn't >>(isn't) able to do so. > MS Exchange Server also stores email in a database. This has some great benefits, but also some horrible side effects. If your database gets corrupted, you are in deep doodoo, and back in the days when I administered an Exchange Server, that happened all too often. As someone mentioned, Cyrus takes a middle approach: it doesn't store the email in a database, but maintains a database that tracks the email to improve speed. It seems to scale well. > > It's a shame it wasn't an OSS project, so we could determine if keeping > mail in a database is a bad idea, or if Oracle just did it poorly. > > The other option is to take what appears to be the best IMAP server out > there (Cyrus) and figure out a way to do real-time mirroring of the > mailboxes. I was wondering if it could be done with Coda, but I don't > know anything about Coda, and it doesn't look like I'll have time to > experiment in the near future. > I played with Coda a few years ago, and it seems to have a lot of potential. I keep promising myself I will look at it again. I recently thought of using it for precisely this scenario, but I had only one server with two drives, and Coda didn't seem to be the way to go in that case. In fact, I just use rsync nightly, and figure I can live with the loss of one day's mail if something dies. There are other distributed filesystems out there in the Linux world, but (IIRC) not many for FreeBSD. I think it is worth looking at Coda for this purpose, although it may have some downside (e.g. not real-time enough) that makes it inappropriate. - Bob