Growing a ZFS pool

Growing a two disk mirror zpool by replacing disks is easy:

1. Replace the first disk with a higher capacity disk (we're going from 2TB to 3TB disks): zpool replace -f pool ata-WDC_WD20EARS-00MVWB0_WD-xxxxxxxxxxxx ata-Hitachi_HDS5C3030BLE630_xxxxxxxxxxxx
2. Wait for the resilver to complete (about 5h).
3. Replace the second disk: zpool replace pool ata-ST2000DL003-xxxxxxxxxxxx ata-ST3000DM001-xxxxxxxxxxxx
4. Wait for the resilver to complete again.
5. Expand the pool by telling it to use the extra space: zpool online -e pool ata-Hitachi_HDS5C3030BLE630_xxxxxxxxxxxx
6. Just in case, tell the pool to expand also the other disk: zpool online -e pool ata-ST3000DM001-xxxxxxxxxxxx

Thanks to the following links for describing the procedure:

http://www.itsacon.net/computers/unix/growing-a-zfs-pool/

http://www.itsacon.net/computers/unix/growing-a-zfs-pool-update/