[OpenIndiana-discuss] Migrating to smaller root pool

[Peter Tribble]

On Sun, Mar 30, 2014 at 4:27 AM, Reginald Beardsley <pulaskite at yahoo.com>wrote:

> I'm trying to migrate to a smaller root pool so I can put /export in a
> RAIDZ1 and use a 3 way mirror for the root pool.  So far I've been soundly
> thrashed.  I copied the rpool contents over to npool w/ "zfs send -R" and
> installed grub. When I boot the new disk, grub comes up with the menu, but
> then complains it can't find the filesystem.  I used a dedicated Solaris
> disk and a 100 GB s0 slice.
>
> This is an existing system that I don't want to rebuild, so the way I
> built my N40L won't work until I get the first bootable pool.
>
> Hints or suggestions?  This is very similar to doing a bare metal
> recovery, so I have a strong interest in figuring this out.
>

There are 3 steps in doing this (and in any installation or
upgrade, come to that.

1. Set up the pool correctly, some or most of this will be picked
up by the zfs send, but you want failmode=continue set on the
pool, and you need to set the bootfs property on the new pool
to be the name of the dataset containing your root file system

2. Create the boot sign. On a normal rpool it would be

touch /rpool/boot/grub/bootsign/pool_rpool
echo "pool_rpool" > /rpool/etc/bootsign

and you will need to change both of those if you change the
name of the pool.

3. Have grub match the boot sign you set in 2, in particular
the findroot and bootfs lines have to match. For example, with
the pool called rpool and the boot sign called pool_rpool, they
say:

findroot (pool_rpool,0,a)
bootfs rpool/ROOT/openindiana

So if you change the pool name from rpool to npool,
you'll probably have to:

/usr/sbin/zpool set bootfs=npool/ROOT/openindiana npool
rm /npool/boot/grub/bootsign/pool_rpool
touch /npool/boot/grub/bootsign/pool_npool
echo "pool_npool" > /npool/etc/bootsign

and replace any rpool with npool in /npool/boot/grub/menu.lst

-- 
-Peter Tribble
http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/