When scrubbing/resilvering a pool it can be counter productive to
cancel the scan and kick of a replace operation to a hot spare
when encountering checksum errors. In this case, the best course
of action is to allow the scrub/resilver to complete as quickly
as possible and to keep the vdevs fully online if possible.
Realistically, this is less of an issue for a RAIDZ since a
traditional resilver must be used and checksums will be verified.
However, this is not the case for a mirror or dRAID pool which is
sequentially resilvered and checksum verification is deferred
until after the replace operation completes.
Regardless, we apply this policy to all pool types since it's
a good idea for all vdevs. Degrading additional vdevs has the
potential to make a bad situation worse. Note the checksum
errors will still be reported as both an event and by
`zpool status`. This change only prevents the ZED from
proactively taking any action.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#13499