ZFS Pool with Different Drive Sizes

Solution 1:

There is a better way, create a single 3 TB pool composed of two mirrors.

zpool create test mirror disk1 disk2 mirror disk3 disk4

with disk1 and disk2 being the 1TB disks and disk3 and disk4 being the 2 TB ones.

Edit:

Should you want to maximize size and do not care that much about performance or best practices, you can partition all the drives with equal size partitions (or slices) and create a 4 TB hybrid pool with a 4 vdev RAIDZ and a 2 vdev mirror.

zpool create -f test raidz d0p1 d1p1 d2p1 d3p1 mirror d0p2 d1p2

Note the "-f" option required to force the command to accept the replication level mismatch.

Solution 2:

This depends on how much data storage you need. You can create two pools of 1TB and 2TB each, using RAID 1. If not, see if you can acquire like-sized disks and try RAID 1+0 or RAIDZ.