From owner-freebsd-questions@FreeBSD.ORG Thu May 20 14:31:47 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 89E7C106566B for ; Thu, 20 May 2010 14:31:47 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (gate6.infracaninophile.co.uk [IPv6:2001:8b0:151:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id F1F368FC1F for ; Thu, 20 May 2010 14:31:46 +0000 (UTC) Received: from seedling.black-earth.co.uk (seedling.black-earth.co.uk [81.187.76.163]) (authenticated bits=0) by smtp.infracaninophile.co.uk (8.14.4/8.14.4) with ESMTP id o4KEVgsh024993 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO) for ; Thu, 20 May 2010 15:31:42 +0100 (BST) (envelope-from m.seaman@infracaninophile.co.uk) Message-ID: <4BF547CE.2090203@infracaninophile.co.uk> Date: Thu, 20 May 2010 15:31:42 +0100 From: Matthew Seaman Organization: Infracaninophile User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <4BF5435F.5090509@esiee.fr> In-Reply-To: <4BF5435F.5090509@esiee.fr> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.96.1 at lucid-nonsense.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=2.0 required=5.0 tests=DKIM_ADSP_ALL,SPF_FAIL, TO_NO_BRKTS_DIRECT autolearn=no version=3.3.1 X-Spam-Level: ** X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on lucid-nonsense.infracaninophile.co.uk Subject: Re: "real time" files mirroring ? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 May 2010 14:31:47 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 20/05/2010 15:12:47, Frank Bonnet wrote: > I'm searching for a software that could perform some kind of real time > mirroring between two (or more) freebsd servers. > > My meaning is to keep up to date some files ( flat and db maps ) used by > Postfix on our MX servers and propagate every change of one or more > files to all the others. That's actually a very hard problem if you really need /real time/ mirroring. If you can stand a delay of a few minutes for changes to propagate, then simply running rsync(1) in a cron job should do -- it's simple to set up, robust and probably quite a lot faster than you expect. You will have to handle any issues to do with file locking and having postfix close and reopen any descriptors on those files if necessary. Otherwise, there are two strategies to consider: * Use a network mounted filesystem. This can work like a charm, or it can be a complete nightmare depending on what postfix needs to do with the shared files. Locking and exclusive access tends to be a problem. You'ld need to look at something like HAST if you want a resilient solution, or your fileserver will be a single point of failure. * Use a network database -- in this case, I'd think LDAP would be a good choice. This is pretty fast in operation, and you can make it resilient pretty easily by replicating the database. Downside is extra work when setting everything up. Cheers, Matthew - -- Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.14 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkv1R84ACgkQ8Mjk52CukIx/QQCeM042jig7+Ux0PKMuidRjudsN w2QAnAn2KLJEW3zh0ElPM2xTd9ESmxQE =wpzh -----END PGP SIGNATURE-----