Mirroring ZFS rpool

OK, time to mirror my rpool. Apparently, it rendered for that works with FreeBSD, but does not with Solaris. (WTF!?)

# zpool attach rpool c0t0d0 c0t1d0
cannot label 'c0t1d0': EFI labeled devices are not supported on root pools.

Ewww... :-(

Here is the steps to cure this illness:

1. format -e will give you all the drives available.
2. If you found one it needs to be formatted, use fdisk and create 100% Solaris2 partition.
3. Your drive supposed to be in /dev/rdsk/ somewhere (don't forget to look in "rdsk", instead in "dsk"). In my case /dev/rdsk/c0t1d0
4. Fix broken bones for the Disk Format:
   prtvtoc /dev/rdsk/c0t0d0 | fmthard -s - /dev/rdsk/c0t1d0
   Then fmthard should tell you something like: "New volume table of the contents now in place". If it didn't — you're out of luck and try to figure out why. :-)
5. Try to attach a drive to rpool, but it may scream, something like this:
   zpool attach rpool c0t0d0 c0t1d0
   invalid vdev specification
   use '-f' to override the following errors:
   /dev/dsk/c0t0d0 overlaps with /dev/dsk/c0t1d0
   
   Well, so be it. Use '-f' option to force it:
   
   zpool attach -f rpool c0t0d0 c0t1d0
   
   Please be sure to invoke installgrub(1M) to make 'c0t1d0' bootable.
   Make sure to wait until resilver is done before rebooting.
6. Normally, you're done: zpool status should show you a mirrored rpool. But you're almost there: still you need to install GRUB.
7. Install GRUB this way:
   installgrub -m /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c0t1d0

Basically this is it, now you might try to boot from another drive. But wait your rpool resilvered though... :-)