From owner-freebsd-isp@FreeBSD.ORG Tue Jun 20 14:15:37 2006 Return-Path: X-Original-To: freebsd-isp@freebsd.org 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 99F5916A479 for ; Tue, 20 Jun 2006 14:15:37 +0000 (UTC) (envelope-from b.candler@pobox.com) Received: from rune.pobox.com (rune.pobox.com [208.210.124.79]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0AA6B43D58 for ; Tue, 20 Jun 2006 14:15:33 +0000 (GMT) (envelope-from b.candler@pobox.com) Received: from rune (localhost [127.0.0.1]) by rune.pobox.com (Postfix) with ESMTP id 167EC79CAC; Tue, 20 Jun 2006 10:15:55 -0400 (EDT) Received: from mappit.local.linnet.org (212-74-113-67.static.dsl.as9105.com [212.74.113.67]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by rune.sasl.smtp.pobox.com (Postfix) with ESMTP id 948D179BA9; Tue, 20 Jun 2006 10:15:53 -0400 (EDT) Received: from lists by mappit.local.linnet.org with local (Exim 4.61 (FreeBSD)) (envelope-from ) id 1Fsh0q-0001Uz-Mb; Tue, 20 Jun 2006 15:15:28 +0100 Date: Tue, 20 Jun 2006 15:15:28 +0100 From: Brian Candler To: Francisco Reyes Message-ID: <20060620141528.GA5731@uk.tiscali.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Cc: FreeBSD ISP Subject: Re: NFS automounting. Stable for mail servers? X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Jun 2006 14:15:37 -0000 On Mon, Jun 19, 2006 at 05:24:01PM -0400, Francisco Reyes wrote: > Our setup has a number of front end mail machines accesing nfs servers. > To distribute the load we create directories like > /mail-server1 > /mail-server2 > /mail-server3 > > Each of the front end machines mounts all the servers from fstab. Problem > with that is that if loading from fstab if one of the nfs servers freezes > the front end machines may have problems while trying to access the downed > nfs server. That's true, but you'd want to be a bit careful with an automounter; you don't want your MTA to create /mail-server1/u/s/username/Maildir on the front-end's local disk if /mail-server1 was not mounted! What would you expect the front-end to do if a user whose mail is on /mail-server1 connects, but /mail-server1 is down? You could add a check to the application code to check for this case. Or, perhaps more simply, you could just use a 'soft mount' for NFS, and let it fail. I've not tested this myself. I've built clusters around Netapps and they are too reliable :-) As for automount, I don't use that either, but I wouldn't expect much problem if you were just auto-mounting /mail-server1, /mail-server2, /mail-server3 and leaving them mounted. I expect the problems you refer to are when user1 connects and you automount /mail-server1/u/s/user1/ (that is, thousands of automounts and unmounts taking place all the time) Regards, Brian.