From owner-freebsd-geom@FreeBSD.ORG  Tue Jan  2 05:25:42 2007
Return-Path: <owner-freebsd-geom@FreeBSD.ORG>
X-Original-To: freebsd-geom@freebsd.org
Delivered-To: freebsd-geom@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id D215116A407
	for <freebsd-geom@freebsd.org>; Tue,  2 Jan 2007 05:25:42 +0000 (UTC)
	(envelope-from gpalmer@freebsd.org)
Received: from noop.in-addr.com (noop.in-addr.com [208.58.23.51])
	by mx1.freebsd.org (Postfix) with ESMTP id 9935413C44C
	for <freebsd-geom@freebsd.org>; Tue,  2 Jan 2007 05:25:42 +0000 (UTC)
	(envelope-from gpalmer@freebsd.org)
Received: from gjp by noop.in-addr.com with local (Exim 4.54 (FreeBSD))
	id 1H1bmZ-000NV0-IG; Tue, 02 Jan 2007 00:01:51 -0500
Date: Tue, 2 Jan 2007 00:01:51 -0500
From: Gary Palmer <gpalmer@freebsd.org>
To: Ivan Voras <ivoras@fer.hr>
Message-ID: <20070102050151.GA90174@in-addr.com>
Mail-Followup-To: Ivan Voras <ivoras@fer.hr>, freebsd-geom@freebsd.org
References: <975053160612310913t3dadcc02yfac58f6fbf0a49df@mail.gmail.com>
	<enbim8$d91$1@sea.gmane.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <enbim8$d91$1@sea.gmane.org>
Cc: freebsd-geom@freebsd.org
Subject: Re: Recommended gmirror solution with swap?
X-BeenThere: freebsd-geom@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: GEOM-specific discussions and implementations
	<freebsd-geom.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-geom>,
	<mailto:freebsd-geom-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-geom>
List-Post: <mailto:freebsd-geom@freebsd.org>
List-Help: <mailto:freebsd-geom-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-geom>,
	<mailto:freebsd-geom-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 02 Jan 2007 05:25:42 -0000

On Mon, Jan 01, 2007 at 07:07:59PM +0100, Ivan Voras wrote:
> Michael Knoll wrote:
> > I am planning on converting my FreeBSD machine to use gmirror on two
> > 40gig drives.  Reading the handbook and other sites with instructions
> > on configuring gmirror, I notice they all disable swap.  Is this
> > acceptable?  Is it expected swap be on another drive?  If so, is there
> > a solution which I can keep the swap on the mirror. as I don't have
> > another drive?
> 
> There's no technical problem with it, it's more a matter of organization
> and convenience. For example: you don't really need the swap to survive
> a crash, so there's no need to introduce the overhead of mirroring it -
> better to leave 2x the space configured as swap area. If you have more
> than one area, the system should take advantage of it and use both to
> maximize speed (in theory this should work as an implicit RAID0 across
> the swap areas).

Except in the case where a drive holding some swapped out memory goes bad
and the system panics or crashes as a result.  It might not make as
much sense for desktops, but if I were (still) building servers I'd
mirror everything that the system depended on to run.