Convert the most basic ZFS pool, a system with a single disk, to a Mirror or Stripe.

Current Setup:

• We have a single disk attached to our system, /dev/da1
• This disk is used as a simple zfs pool, tank
• You bought another disk and want to mirror the pool to the new disk, /dev/da2

Make sure you’ve got the disk names correct.

Use dmesg to see the system messages, to determine which disk is which.

Delete any existing partitions if needed.

sudo gpart destroy -F /dev/da2

Format the drive as gpt:

sudo gpart create -s gpt /dev/da2

Create a zfs partition:

sudo gpart add -t freebsd-zfs /dev/da2

This new partition is /dev/da2p1, and will nbe added to the existing partition next.