Using GTP and glabel for ZFS arrays

[Tom Evans]

On Thu, Jul 22, 2010 at 8:22 PM, Pawel Tyll <ptyll at nitronet.pl> wrote:
>> 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.
>

If you do do it like this, be sure to leave the drive you are
replacing attached to the array. Otherwise, in a raidz, if you were to
suffer a disk failure on one of the other disks whilst
replacing/growing the array, your raidz would be badly broken.

Other than that, I can thoroughly recommend this method, I had data on
2 x 1.5 TB drives, and set up my raidz initially with 4 x 1.5 TB, 2 x
0.5 TB, copying data off the 1.5 TB drives onto the array and
replacing each 0.5 TB drive when done.

Cheers

Tom