Comment by mnw21cam

Agreed. I have a couple of servers each with 168 hard drives, about 6 years old. A few hard drives are starting to fail. ZFS counts read errors (the drive reported an error because its checksum didn't match) and checksum errors (the drive returned data that was actually incorrect and ZFS caught it with a checksum). I have seen lots of read errors, but not a single checksum error yet. Though these are server-grade drives, which might be better than consumer-grade.