From owner-freebsd-questions@FreeBSD.ORG Wed Jan 6 21:44:47 2010 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 BF8FB1065672 for ; Wed, 6 Jan 2010 21:44:47 +0000 (UTC) (envelope-from amsibamsi@gmail.com) Received: from mail-fx0-f227.google.com (mail-fx0-f227.google.com [209.85.220.227]) by mx1.freebsd.org (Postfix) with ESMTP id 4E0A78FC0C for ; Wed, 6 Jan 2010 21:44:46 +0000 (UTC) Received: by fxm27 with SMTP id 27so3178390fxm.3 for ; Wed, 06 Jan 2010 13:44:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:subject:mime-version :content-type:from:in-reply-to:date:cc:content-transfer-encoding :message-id:references:to:x-mailer; bh=EC8msCVqlGHxan7hsSS3A9CnPTLgK3Mil5EwjT/XiuY=; b=Vk+ngzJCy7WPJ9qjZiXRm3qfl10OrOCf9y1dICqfXU/tKccW9WSmCTu5pva0FLwyqz h8gXg/95lNJjFEEO3Oo5eb12hSVPTh3/pADWITC+14Jf6AF+LSaF/HdV7k8yDmq8NUBu xyjS/R1XrpOq5ONUDc+mWl6gtw7g0Lbp1IgtM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; b=L4dLCt+W85xe6zHXEKEILMSILqHtWQSSBFY92NwzFUyccLChpi2ZbM/AAn9XiSN/1b 9XCAU1HANB+eRtiWP1M1zW7U/OUSxL3z23ahlt46B9RwroM1VBFBEVDDYU8/GMjJXlZK /0qsPaVuiofDIQofpRFd4HVdHqmycZhtV5fWI= Received: by 10.223.18.145 with SMTP id w17mr221562faa.66.1262814282641; Wed, 06 Jan 2010 13:44:42 -0800 (PST) Received: from silversurfer.l.ttyv0.net (80-219-19-168.dclient.hispeed.ch [80.219.19.168]) by mx.google.com with ESMTPS id p9sm30744164fkb.44.2010.01.06.13.44.41 (version=SSLv3 cipher=RC4-MD5); Wed, 06 Jan 2010 13:44:41 -0800 (PST) Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset=us-ascii From: Anselm Strauss In-Reply-To: Date: Wed, 6 Jan 2010 22:44:39 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <4284CE82-9BE5-463D-AEFC-299CA7347C7C@gmail.com> References: <15FCFBD0-9B68-421B-A99C-1038BAD61362@gmail.com> To: krad X-Mailer: Apple Mail (2.1077) Cc: freebsd-questions@freebsd.org Subject: Re: Booting from ZFS raidz 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, 06 Jan 2010 21:44:47 -0000 On Jan 6, 2010, at 21:37 , krad wrote: > 2010/1/6 Anselm Strauss > Hi, >=20 > I'm experimenting with a ZFS only system and booting from it in = VirtualBox. Thanks to various mails and forum posts from the net I have = a working scenario with booting from a ZFS mirror. However, I can't get = the thing to work with raidz with the exactly same setup, except that = the pool is now raidz instead of mirror and there is one more disk. I = feel sure I have all the stuff with partitioning, boot loader = installation, etc. right. I tested this with version 8.0-RELEASE on = 64bit. >=20 > Now, before I go into detailed explaining, is raidz really supported? = I always get the following error after it says "FreeBSD/i386 bootstrap = loader, Revision 1.1": >=20 > ZFS: i/o error - all block copies unavailable > ZFS: can't read MOS object directory > (repeats a lot) > Can't find root filesystem - giving up > can't load 'kernel' >=20 > I think the "MOS" message comes from zfs_mount_root() in = /usr/src/sys/boot/zfs/zfsimpl.c. I asume that is the point when = /boot/loader has been loaded and now wants to load the kernel into = memory. After that error I'm in the loader prompt. When I try to load = any file I always get the same error as above. >=20 > Anyone any ideas? >=20 > Thanks, > Anselm_______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to = "freebsd-questions-unsubscribe@freebsd.org" >=20 > Opensolaris doesnt support booting off raidz yet so id be surprised if = you managed to, as i doubt all the relevent code is in the loader, and = robust enough yet. I have seen a few hacks mentioned in places that = might get it to work, bit these are unsupported and might flake out at = any time. >=20 > Also why do you need a raidz for the os? It implys you might be mixing = data on the pool as well. This isnt best practice, and you are best off = having a separate pool for os and data. If you have 3+ drives, gpt it = into 3 or 4 chunks dependent on whether you want swap on a zvol. Have = and x way mirror for the os and then the last and biggest gpt slice use = for your raidz data. Better still have the os and data on separate = spindles I was just out for maximum flexibility and easiness. Having just one = pool gives you the most possibilities in resizing data sets. Using = partitions always imposes some hard limits that are sometimes different = to overcome when you want to re-layout you filesystems. I like the idea = of ZFS that the boundaries between filesystems (or data sets) are just = quotas and reservations, instead of low-level address borders as with = partitions. But then again, as you mentioned, one might want to make = multiple pools for best performance. At least I want to have the system = data on a redundant volume, but you are right I could just make a = separate mirror for that. By the way, I also tested to boot from a degraded mirror, which worked = perfectly well. You just have to make sure that the boot loader stages = are installed on all drives. Thanks, Anselm