ZFS on 4K drives - Expanding zpool and adding spares (gnop method)

[Negasi Gerima]

Hello,

I apologize if this topic is redundant, but I couldn't find an exact 
answer to my specific question. So here goes.

I recently decided to expand the storage in my home server with a bunch 
of 1.5Tb Samsung 4K hard drives. Using the guide at the following link I 
was able to use the "gnop method" in order to align the drives for use 
with 4K sectors:

http://ivoras.net/blog/tree/2011-01-01.freebsd-on-4k-sector-drives.html

My question to the list is this, now that my new zpool is created and 
I've made sure the drives are using the correct layout, how would I go 
about expanding the zpool in the future with additional drives and/or 
spares? I emailed the author of the article but received a reply that I 
found terse at best.

I'm assuming that I would have to create a new gnop device for each 
additional hard drive, and then add those gnop devices to the pool.

For example, if I had a pool called 'datastore' and three additional 
drives /dev/ad10, /dev/ad12, & /dev/ad14. I'm assuming I should use the 
following steps to achieve my goal:

1. Create the gnop devices /dev/ad10.nop, /dev/ad12.nop, and /dev/ad14.nop,

2. Add these devices to the zpool with 'zpool add datastore 
/dev/ad10.nop /dev/ad12.nop'

3. Export the zpool with 'zpool export datastore'

4. Destroy gnop devices with 'gnop destroy /dev/da10.nop /dev/da12.nop 
/dev/da14.nop'

5. Re-import the zpool data with 'zpool import datastore'

Can someone please confirm that this method is correct, or if there is a 
more streamlined method for achieving the desired goal?

Thanks in advance,

NG