From owner-freebsd-fs@FreeBSD.ORG Mon Apr 2 16:00:14 2012 Return-Path: Delivered-To: freebsd-fs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9F9EA106566C for ; Mon, 2 Apr 2012 16:00:14 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 610CB8FC15 for ; Mon, 2 Apr 2012 16:00:14 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.5/8.14.5) with ESMTP id q32G0EhU019683 for ; Mon, 2 Apr 2012 16:00:14 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.5/8.14.5/Submit) id q32G0Eb1019682; Mon, 2 Apr 2012 16:00:14 GMT (envelope-from gnats) Date: Mon, 2 Apr 2012 16:00:14 GMT Message-Id: <201204021600.q32G0Eb1019682@freefall.freebsd.org> To: freebsd-fs@FreeBSD.org From: George Hartzell Cc: Subject: Re: kern/166566: [zfs] zfs split renders 2 disk (MBR based) mirror unbootable X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: George Hartzell List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Apr 2012 16:00:14 -0000 The following reply was made to PR kern/166566; it has been noted by GNATS. From: George Hartzell To: Andriy Gapon Cc: bug-followup@FreeBSD.org, hartzell@alerce.com Subject: Re: kern/166566: [zfs] zfs split renders 2 disk (MBR based) mirror unbootable Date: Mon, 2 Apr 2012 08:47:53 -0700 Thanks for following up on this. Andriy Gapon writes: > > A few things missing from your port: > > 1. "Doesn't boot" is quite a poor description in comparison with > other details that you provided. You should give more detailed > information of the boot failure. As the kernel is loading it fails to mount the root partition and presents one with the minimal mountroot dialog. Attempting to boot from zfs:zroot or zfs:zsplitroot fails. I remember that a question mark lists various other devices but don't remember the particulars. > 2. gpart information for ada3 Identical to ada1. Both disks have an MBR with one slice, which has a BSD label with two partitions, a (926GB, type freebsd-zfs) and b (5.5GB, type freebsd-swap). (delicious)[8:45am]~>>gpart show ada1 => 63 1953525105 ada1 MBR (931G) 63 1953525105 1 freebsd [active] (931G) (delicious)[8:45am]~>>gpart show ada1s1 => 0 1953525105 ada1s1 BSD (931G) 0 1941962752 1 freebsd-zfs (926G) 1941962752 11562353 2 freebsd-swap (5.5G) (delicious)[8:46am]~>>gpart show ada3 => 63 1953525105 ada3 MBR (931G) 63 1953525105 1 freebsd [active] (931G) (delicious)[8:46am]~>>gpart show ada3s1 => 0 1953525105 ada3s1 BSD (931G) 0 1941962752 1 freebsd-zfs (926G) 1941962752 11562353 2 freebsd-swap (5.5G) Both have boot bits set up like this: gpart bootcode -b /boot/boot0 adaX dd if=/boot/zfsboot of=/dev/adaXs1 count=1 dd if=/boot/zfsboot of=/dev/adaXs1a skip=1 seek=1024 > 3. You don't say which disk ended up as zroot and as zsplitroot > after the split. zpool status showed only zroot ada3s1a and zpool import showed zsplitroot ada1s1a > 4. You don't say which disk is configured as a boot disk in BIOS. This is a mac pro (tower), so BIOS is kind of a slippery concept. I leave the 'startup disk' set to the (other) OS X disks. On power up I hold down the option key and am presented with a dialog from which I can select any of the bootable devices in the box. When things are working correctly I can boot from either of the disks in the ZFS mirror and things go well. Now that I've upgraded I can even pull one of the disks before powering up and boot from the other (older zfs bootstrapping stuff used to have a problem with broken mirrors). After the zfs split I am unable to boot from either disk. g.