Using GTP and glabel for ZFS arrays

[Dan Langille]

On 7/22/2010 9:22 PM, Pawel Tyll 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.

Pawell and I had an online chat about part of my strategy.  To be clear:

I have a 5x2TB raidz1 array.

I have 2x2TB empty HDD

My goal was to go to raidz2 by:
- copy data to empty HDD
- redo the zpool to be raidz2
- copy back the data
- add in the two previously empty HDD to the zpol

I now understand that after a raidz array has been created, you can't 
add a new HDD to it.  I'd like to, but it sounds like you cannot.

"It is not possible to add a disk as a column to a RAID-Z, RAID-Z2, or 
RAID-Z3 vdev." http://en.wikipedia.org/wiki/ZFS#Limitations

So, it seems I have a 5-HDD zpool and it's going to stay that way.





-- 
Dan Langille - http://langille.org/