From owner-freebsd-hackers@FreeBSD.ORG Sat Oct 11 21:40:56 2008 Return-Path: Delivered-To: freebsd-hackers@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F07821065688; Sat, 11 Oct 2008 21:40:56 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.delphij.net (delphij-pt.tunnel.tserv2.fmt.ipv6.he.net [IPv6:2001:470:1f03:2c9::2]) by mx1.freebsd.org (Postfix) with ESMTP id 929928FC14; Sat, 11 Oct 2008 21:40:56 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.geekcn.org (tarsier.geekcn.org [211.166.10.233]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by tarsier.delphij.net (Postfix) with ESMTPS id B952D28449; Sun, 12 Oct 2008 05:40:55 +0800 (CST) Received: from localhost (tarsier.geekcn.org [211.166.10.233]) by tarsier.geekcn.org (Postfix) with ESMTP id 51414101D555; Sun, 12 Oct 2008 05:40:55 +0800 (CST) X-Virus-Scanned: amavisd-new at geekcn.org Received: from tarsier.geekcn.org ([211.166.10.233]) by localhost (mail.geekcn.org [211.166.10.233]) (amavisd-new, port 10024) with ESMTP id z0O200vJ4hwx; Sun, 12 Oct 2008 05:40:50 +0800 (CST) Received: from delta.delphij.net (c-76-103-40-85.hsd1.ca.comcast.net [76.103.40.85]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tarsier.geekcn.org (Postfix) with ESMTPSA id 0828E101C86B; Sun, 12 Oct 2008 05:40:48 +0800 (CST) DomainKey-Signature: a=rsa-sha1; s=default; d=delphij.net; c=nofws; q=dns; h=message-id:date:from:reply-to:organization:user-agent: mime-version:to:cc:subject:references:in-reply-to: x-enigmail-version:openpgp:content-type:content-transfer-encoding; b=ja7xySETppg3Gg8FmKeIdQQIRYDPvfgYskvhBRVtDYpOcjYHkFs6I9BtuwDyI7Idy DLh50/PiHApXgQK5xPFsg== Message-ID: <48F11D5E.7090108@delphij.net> Date: Sat, 11 Oct 2008 14:40:46 -0700 From: Xin LI Organization: The Geek China Organization User-Agent: Thunderbird 2.0.0.17 (X11/20080926) MIME-Version: 1.0 To: Matthew Dillon References: <200810111810.m9BIAGPw059975@apollo.backplane.com> In-Reply-To: <200810111810.m9BIAGPw059975@apollo.backplane.com> X-Enigmail-Version: 0.95.7 OpenPGP: id=18EDEBA0; url=http://www.delphij.net/delphij.asc Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@FreeBSD.org, Jeremy Chadwick , Mike Meyer Subject: Re: ZFS boot X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: d@delphij.net List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Oct 2008 21:40:57 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, Matt, Matthew Dillon wrote: [...] > /boot can be as complex as boot2 allows. There's nothing preventing > it from being RAIDed if boot2 supported that, and there's nothing > preventing it (once you had ZFS boot capabilities) from being ZFS > using a topology supported by boot2. Having a sparate /boot allows > your filesystem root to use topologues boot2 would otherwise not > support. I believe that it's a good idea to separate / from the zpool for other file systems, or even use a UFS /. My experience with ZFS on my laptop shows that disk failures can be more easily fixed if there are some utilities available in the UFS /, even when ZFS is used as /. Another issue with a ZFS / is that the snapshot rollback feature generally does not work on / since it needs the mountpoint to be unmounted. One thing that I found very useful is the new GPT boot feature on 8.0, which also works on older BIOS because the protected MBR would deal with the bootstrap to the actual GPT boot. Now we have a 15-block sized gptboot that can boot FreeBSD from UFS, however this 'boot' can be in virtually any size that the BIOS supports, so we can embed more logic there. Cheers, -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkjxHV0ACgkQi+vbBBjt66CpXgCfWstsxNc3B4xOzNTxz9/kdl3Y /WYAnjqiV5H8xQYxGgZTnwWieuG6ZZij =LH+x -----END PGP SIGNATURE-----