How to add disk to pool zfs?

Question

ZFS

Added a 480GB drive.
Before that, there were 2 disks of 240GB each in raid 1.
The output of zpool status

pool: rpool
 state: ONLINE
  scan: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            sda2    ONLINE       0     0     0
            sdb2    ONLINE       0     0     0

zpool list output

NAME    SIZE  ALLOC   FREE  EXPANDSZ   FRAG    CAP  DEDUP  HEALTH  ALTROOT
rpool   222G   110G   112G         -    59%    49%  1.00x  ONLINE  -

Or would it be more correct to create a new pool and work with it already?

Answer 1

It is better to add vdevs with the same redundancy to the pool. In your case, it is better to make a separate pool from a single device. And in case of failure of a single device, you will not lose the entire pool.

Answer 2

And how do you want to add a disk to raid one? That is, you also want to have a third copy of the disk, that is,