From owner-freebsd-questions@FreeBSD.ORG Tue Oct 21 05:19:35 2008 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 841A51065673 for ; Tue, 21 Oct 2008 05:19:35 +0000 (UTC) (envelope-from k0802647@telus.net) Received: from outbound05.telus.net (outbound05.telus.net [199.185.220.224]) by mx1.freebsd.org (Postfix) with ESMTP id 32AD18FC17 for ; Tue, 21 Oct 2008 05:19:34 +0000 (UTC) (envelope-from k0802647@telus.net) Received: from priv-edtnaa04.telusplanet.net ([75.157.26.132]) by priv-edtnes90.telusplanet.net (InterMail vM.7.08.02.00 201-2186-121-20061213) with ESMTP id <20081021051934.BQAY25082.priv-edtnes90.telusplanet.net@priv-edtnaa04.telusplanet.net> for ; Mon, 20 Oct 2008 23:19:34 -0600 Received: from oliver.bc.lan (d75-157-26-132.bchsia.telus.net [75.157.26.132]) by priv-edtnaa04.telusplanet.net (BorderWare Security Platform) with ESMTP id B3E22923342107E1 for ; Mon, 20 Oct 2008 23:19:33 -0600 (MDT) Received: from [10.111.111.112] (unknown [10.111.111.112]) by oliver.bc.lan (Postfix) with ESMTP id 7C714646B; Mon, 20 Oct 2008 22:19:33 -0700 (PDT) Message-ID: <48FD6665.5000102@telus.net> Date: Mon, 20 Oct 2008 22:19:33 -0700 From: Carl User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: gjournal: journaled slices vs. journaled partitions 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: Tue, 21 Oct 2008 05:19:35 -0000 My goal is to build a 2-disk server configured with gmirror and gjournal for maximum reliability. There will never be a second operating system on the system, but I prefer not to freak out any non-FreeBSD repair tools that might be used, so I will use compatibility instead of dangerously dedicated mode. This means I need one slice, but see no reason for more. Inside that one slice will be the usual array of partitions (ie. /, swap, /var, /tmp, /usr, /data). Now, I think gmirror allows me to mirror the entire drive rather than forcing me to do per-slice or even per-partition mirroring. I'm looking for the simplest in-field replacement procedure when one of the drives dies and I imagine a whole drive mirror achieves this. Am I right? gjournal, OTOH, has me really confused. The man page for gjournal(8) specifically does not recommend that small partitions be journaled. I assume that's because the journal provider rivals the partition in size and is therefore overhead heavy. It seems to me, though, that if I can journal the slice as a whole instead of per-partition journaling, that there will essentially then be only one journal provider for the combination of all partitions (ie. slice) and that the aforementioned overhead becomes minor. Having smaller partitions included in journaling seems like a good thing to me. So how do I achieve per-slice journaling instead of per-partition? Every time I read up on someone else's gjournal implementation, it seems to end with adding .journal entries to /etc/fstab. Am I trying to achieve the impossible or ill-advised here? Carl / K0802647