Using GTP and glabel for ZFS arrays

[Pawel Tyll]

> I do not think I can adjust the existing zpool on the fly.  I think I
> need to copy everything elsewhere (i.e the 2 empty drives).  Then start
> the new zpool from scratch.
You can, and you should (for educational purposes if not for fun :>),
unless you wish to change raidz1 to raidz2. Replace, wait for
resilver, if redoing used disk then offline it, wipe magic with dd
(16KB at the beginning and end of disk/partition will do), carry on
with GPT, rinse and repeat with next disk. When last vdev's replace
finishes, your pool will grow automagically.