There is a ZFS pool with raidz1 in it. The pool is created on top of three 2TB drives using the whole disk and a 2TB partition on a 3TB drive.

What is the recommended process to reconfigure the pool to use the whole 3TB disk instead of the partition?

I read a lot the zfs manual (man zpool) but I'm not sure which commands should be used: attach/detach or online/offline and the pool shold be exported or not.

Because the the array is almost full of data, I don't like the idea to just stab in the dark and play with it.

Also, I ran zpool scrub multiple times and it finished without errors.