Date: Sun, 12 Feb 2012 14:25:52 -0500 From: Kurt Lidl <lidl@pix.net> To: Gavin Mu <gavin.mu@gmail.com> Cc: freebsd-sparc64@FreeBSD.org Subject: Re: sparc64/165025: [PATCH] zfsboot support for sparc64 Message-ID: <20120212192552.GA55852@pix.net> In-Reply-To: <201202121530.q1CFU8fH047653@freefall.freebsd.org> References: <201202121530.q1CFU8fH047653@freefall.freebsd.org>
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On Sun, Feb 12, 2012 at 03:30:08PM +0000, Gavin Mu wrote:
> The following reply was made to PR sparc64/165025; it has been noted by GNATS.
>
> From: Gavin Mu <gavin.mu@gmail.com>
> To: Marius Strobl <marius@alchemy.franken.de>
> Cc: bug-followup@freebsd.org
> Subject: Re: sparc64/165025: [PATCH] zfsboot support for sparc64
> Date: Sun, 12 Feb 2012 22:59:12 +0800
>
> >> Known Limitations:
> >> 1. only zpool on a whole disk is supported, zfs boot from zpool in VTOC8 partitions may not work.
> >
> > Uhm, are you sure you didn't have (the remnants) of a VTOC label on
> > the disk? I'd expect the firmware to refuse to boot from a disk not
> > having one.
> Sorry, it is my fault not writing this here. A fake VTOC8 label is
> still required, and it is not conflict with zpool on the whole disk,
> since ZFS reserved the first 8KB block unused. the VTOC8 table and
> boot1 (or zfsboot) code can be in this 8KB block. command `zpool
> create` will not destroy the VTOC8 table and the boot1 code.
> >
> >> 2. boot from mirror/raidz is not supported due to limited dev environment.
> >
> > Could you also tackle these remaining bits or at least describe what
> > it would take to support booting from a zpool in a VTOC label, mirror
> > and raidz?
> I do not have enough hardware to test booting from mirror/raidz disks,
> so I focus only on booting from one single disk in this PR.
> The default zfs_dev.dv_init() traverse all possible disks and
> slices/partitions to find all zpool vdev, I simply changed the
> behavior to read from one single disk only then it is easy to know
> which zpool should be used to boot (there will be only one). To
> support booting from mirror/raidz, all disks/slices must be traversed
> and it is needed to decide which zpool to boot.
>
> booting from a zpool in VTOC8 label should be possible for me to do
> dev/test, I need a little more VTOC8 knowledge and will try it later.
> >
> >>
> >> >How-To-Repeat:
> >> NA.
> >> >Fix:
> >> generic steps:
> >> 1. build zfsboot and zfsloader
> >> 2. create zpool on your disk
> >> # zpool create tank /dev/<your disk, ie. ada0>
> >> 3. export the zpool
> >> # zpool export tank
> >> 4. install zfsboot
> >> # dd if=boot1 of=/dev/<your disk, ie. ada0> bs=512 skip=1 oseek=1 conv=notrunc
> >
> > Assuming there is a VTOC8 label, this could also be done using `gpart -b`,
> > no?
> Yes, but I think we should keep the zpool exported, otherwise this
> command may fail.
I think you actually want to do this:
gpart bootcode -p /boot/boot1 ${disk}
There isn't really "boot0" type code for sparc64, as you know, but
there is partition code ("boot1").
I think the introduction of booting from ZFS on sparc64 hardware
is a very exciting development. I had just recently gone through
the process of installing FreeBSD 9.0 onto a mostly ZFS sparc64
setup -- just using UFS for the boot filesystem. One of the things
that I worked out was how to do it all with 'gpart' and not having
to rely on "sunlabel", "dd", etc... Ironically, the day after I
figured out most of this stuff, there as a pointer to a guide written
in German that explained a bunch of it posted to the mailing list:
http://lists.freebsd.org/pipermail/freebsd-sparc64/2011-November/008112.html
Anyway...
for disk in da0 da1
do
for i in 1 2 4 5 6 7
do
gpart delete -i $i ${disk}
done
gpart destroy ${disk}
gpart create -s vtoc8 ${disk}
gpart add -t freebsd-ufs -s 1g ${disk}
gpart add -t freebsd-swap -s 16g ${disk}
gpart add -t freebsd-zfs ${disk}
# put bootcode at start of root partition
gpart bootcode -p /boot/boot1 ${disk}
done
[ then stuff about setting up the gmirror etc]
-Kurt
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