[muth02446]

What I am curious about: where zfs checksum failures the only symptom of the bad disks or where there SMART failures as well?

[gdevenyi]

In our ZFS JBOD setup with 90HDDs we scrub regularly and never find checksum errors. Instead, we might get a few recoverable read errors, but more likely, no SMART warnings, just sudden drive failure disappearing from the bus.