From owner-freebsd-current@FreeBSD.ORG Fri Jul 18 18:17:26 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6DAD81065681; Fri, 18 Jul 2008 18:17:26 +0000 (UTC) (envelope-from mvolaski@aecom.yu.edu) Received: from mx1.aecom.yu.edu (mx1.aecom.yu.edu [129.98.1.51]) by mx1.freebsd.org (Postfix) with ESMTP id 489CD8FC19; Fri, 18 Jul 2008 18:17:26 +0000 (UTC) (envelope-from mvolaski@aecom.yu.edu) Received: from draco.aecom.yu.edu (draco.aecom.yu.edu [129.98.1.160]) by mx1.aecom.yu.edu (Postfix) with ESMTP id D49EE9F013A; Fri, 18 Jul 2008 14:17:25 -0400 (EDT) X-AuditID: 816201a0-a629cbb0000015ac-48-4880de35839c Received: from smtp2.aecom.yu.edu (smtp2.aecom.yu.edu [129.98.1.62]) by draco.aecom.yu.edu (Symantec Mail Security) with ESMTP id 5D65F718002; Fri, 18 Jul 2008 14:17:25 -0400 (EDT) Received: from [129.98.90.227] (usseinstein.aecom.yu.edu [129.98.90.227]) by smtp2.aecom.yu.edu (Postfix) with ESMTP id 3170DB714; Fri, 18 Jul 2008 14:17:25 -0400 (EDT) Mime-Version: 1.0 Message-Id: In-Reply-To: References: Date: Fri, 18 Jul 2008 14:16:55 -0400 To: Jonathan Hogg From: Maurice Volaski Content-Type: text/plain; charset="us-ascii" ; format="flowed" X-Brightmail-Tracker: AAAAAA== Cc: freebsd-current@freebsd.org, pjd@FreeBSD.org Subject: Re: Would ZFS and gmirror work well together in a two-node failover cluster? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jul 2008 18:17:26 -0000 >Have you considered ZFS snapshots and send/receive? This would allow >you to maintain a consistent (from ZFS' perspective) replica in near >real-time (depending on how frequently the snapshots are taken). Thanks for your suggestion. I'm not sure how that would work in practice either, but is potentially interesting to consider. For one thing, how small can small window of data be, something measured in minutes or hours? And this would be a system that could be moving 100 MB+ per second, so the data could get outdated quickly. Plus, I'm looking for the failover to be automatic and near instantaneous. That is, if I pull the power cord on the primary, could the secondary go hot in under a minute? That's the way it works with heartbeat and DRBD on Linux. Solaris on x86 has a mechanism very similar to DRBD called AVS, although it's only a little more complex, it's Solaris itself that is so different (and perhaps more complex) than Linux that I was thinking FreeBSD might be an alternative. -- Maurice Volaski, mvolaski@aecom.yu.edu Computing Support, Rose F. Kennedy Center Albert Einstein College of Medicine of Yeshiva University