# before
root@filer0:~# zpool list tank
NAME      SIZE   USED  AVAIL    CAP  HEALTH  ALTROOT
tank     1.82T  1.56T   266G    85%  ONLINE  -

root@filer0:~# zpool add tank raidz c2t5d0 c3t2d0 c3t6d0 c2t2d0 c2t6d0

# after
root@filer0:~# zpool list tank
NAME      SIZE   USED  AVAIL    CAP  HEALTH  ALTROOT
tank     6.37T  1.56T  4.81T    24%  ONLINE  -