# To check the integrity of an entire mirror pool,
# and repair it if necessary:
zpool scrub [poolname]
# The command returns immediately, and the scrub
# continues in the background - to view progress:
zpool status [poolname]

# LXF273 recommend using the -L option as follows:
zpool status -L [poolname]
# in order to display linux device names, but as
#  of 2021-10-23 there seemed to be no difference.