There are lots of ways to manage your ZFS pools. This article contains some useful commands and examples. They are suitable for any kind of virtual device configuration including mirrored, RAIDZ or nonredundant.
Replace a disk in a ZFS pool
There will come a point when you will need to replace one of your disks within your ZFS pool. Perhaps a disk has become unavailable, or you are getting read/write errors. The method will be the same whether you have a mirrored or RAIDZ virtual device configuration.
Create a ZFS pool
The Z File System (ZFS) can be used to pool together several disks. For example, three 2TB disks could be connected to your computer to create a single pool with 6TB storage capacity.
Increase ZFS pool by adding larger disks
Eventually your ZFS pool will no longer have enough storage for you. When this happens you will need to add some disks or replace your old disks with new larger ones. Since i no longer have any spare SATA ports, I am going to do the latter, replacing all my 2TB disks with 6TB ones.