From owner-freebsd-fs@FreeBSD.ORG Mon Nov 30 22:56:03 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 264F0106566B for ; Mon, 30 Nov 2009 22:56:03 +0000 (UTC) (envelope-from fbsd@dannysplace.net) Received: from mail.dannysplace.net (mail.dannysplace.net [80.69.71.124]) by mx1.freebsd.org (Postfix) with ESMTP id CEFA08FC0C for ; Mon, 30 Nov 2009 22:56:02 +0000 (UTC) Received: from nas.lan ([203.206.171.212] helo=[192.168.10.10]) by mail.dannysplace.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1NFFA1-000Lbs-IM; Tue, 01 Dec 2009 08:56:02 +1000 Message-ID: <4B144D79.90806@dannysplace.net> Date: Tue, 01 Dec 2009 08:55:53 +1000 From: Danny Carroll User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.1.1) Gecko/20090715 Thunderbird/3.0b3 MIME-Version: 1.0 To: Zaphod Beeblebrox References: <2ae8edf30911300120x627e42a9ha2cf003e847d4fbd@mail.gmail.com> <4B139AEB.8060900@jrv.org> <2ae8edf30911300425g4026909bm9262f6abcf82ddcd@mail.gmail.com> <5f67a8c40911301233s46a2818at9051c4ebbacf7e25@mail.gmail.com> In-Reply-To: <5f67a8c40911301233s46a2818at9051c4ebbacf7e25@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-User: danny X-Authenticator: plain X-Sender-Verify: SUCCEEDED (sender exists & accepts mail) X-Exim-Version: 4.69 (build at 13-Aug-2009 20:22:24) X-Date: 2009-12-01 08:56:02 X-Connected-IP: 203.206.171.212:59473 X-Message-Linecount: 36 X-Body-Linecount: 22 X-Message-Size: 1843 X-Body-Size: 1019 X-Received-Count: 1 X-Recipient-Count: 2 X-Local-Recipient-Count: 2 X-Local-Recipient-Defer-Count: 0 X-Local-Recipient-Fail-Count: 0 X-SA-Exim-Connect-IP: 203.206.171.212 X-SA-Exim-Rcpt-To: zbeeble@gmail.com, freebsd-fs@freebsd.org X-SA-Exim-Mail-From: fbsd@dannysplace.net X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on ferrari.dannysplace.net X-Spam-Level: X-Spam-Status: No, score=-1.3 required=8.0 tests=ALL_TRUSTED,AWL autolearn=disabled version=3.2.5 X-SA-Exim-Version: 4.2 X-SA-Exim-Scanned: Yes (on mail.dannysplace.net) Cc: freebsd-fs Subject: Re: ZFS guidelines - preparing for future storage expansion X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: fbsd@dannysplace.net List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Nov 2009 22:56:03 -0000 On 1/12/2009 6:33 AM, Zaphod Beeblebrox wrote: > I moved from 5x 750G to 5x 1.5T disks this way earlier this year. It takes > a _long_ time. resilvering 750g (they were about 98% full when I did this) > onto the 1.5T disks took about 12 hours each. With work and sleep and other > distractions, it took most of a week to perform the upgrade. And keep in > mind that while you're upgrading, you're vulnerable to data loss (no more > replicas). I suppose RAIDZ2 would make that safer, but more costly. > Would it be possible to mitigate the risk of data loss by marking all ZFS volumes read only? That way if you lose a disk, you could simply put back the old disk. I have no idea if this is possible, I'd imagine ZFS may not be happy to see a drive again that it was told to replace. Also, it might not be appropriate for most production systems, but if you can afford the inconvenience of not being able to write while the array is resilvering then it may be suitable for some. Just a thought.... -D