From owner-freebsd-questions@FreeBSD.ORG Wed Jan 14 20:21:25 2009 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 BE9C910656C3 for ; Wed, 14 Jan 2009 20:21:25 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from mail-out4.apple.com (mail-out4.apple.com [17.254.13.23]) by mx1.freebsd.org (Postfix) with ESMTP id A2DEA8FC20 for ; Wed, 14 Jan 2009 20:21:25 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from relay10.apple.com (relay10.apple.com [17.128.113.47]) by mail-out4.apple.com (Postfix) with ESMTP id 659104E94477; Wed, 14 Jan 2009 12:21:25 -0800 (PST) Received: from relay10.apple.com (unknown [127.0.0.1]) by relay10.apple.com (Symantec Brightmail Gateway) with ESMTP id 49B6028050; Wed, 14 Jan 2009 12:21:25 -0800 (PST) X-AuditID: 1180712f-ac972bb0000012d3-1c-496e4945b4b1 Received: from cswiger1.apple.com (cswiger1.apple.com [17.227.140.124]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by relay10.apple.com (Apple SCV relay) with ESMTP id 32BD028056; Wed, 14 Jan 2009 12:21:25 -0800 (PST) Message-Id: <7C98E2D0-D084-4B6D-9133-F518D5DFF4E5@mac.com> From: Chuck Swiger To: Peter Steele In-Reply-To: <2ACA3DE8F9758A48B8BE2C7A847F91F247A1E1@polaris.maxiscale.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v930.3) Date: Wed, 14 Jan 2009 12:21:25 -0800 References: <2ACA3DE8F9758A48B8BE2C7A847F91F247A1E1@polaris.maxiscale.com> X-Mailer: Apple Mail (2.930.3) X-Brightmail-Tracker: AAAAAA== Cc: freebsd-questions@freebsd.org Subject: Re: Should swap space be mirrored via geom? 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: Wed, 14 Jan 2009 20:21:27 -0000 On Jan 14, 2009, at 8:04 AM, Peter Steele wrote: > We have been debating whether or we should mirror the swap > partitions as > well. I set it up not mirrored based on some articles I read on the > net, > but we're concerned what might happen to a system if a drive died at a > time when the its swap partition contained active pages. My first > reaction would be that the applications bound to these pages would > crash, something that would not happen if we used swap mirroring. If you don't mirror swap space, and a drive goes out, you're almost certain to experience a kernel panic and not just application failures in userland. Unless you have an urgent need for lots of swap space available, it's much better from the standpoint of system reliability to mirror swap also. Regards, -- -Chuck