Scrubbing Software Raid
Seen on Slashdot:
This is why you scrub your RAID arrays once a week. If you're using software RAID on Linux, for example:
# echo check > /sys/block/md0/md/sync_action
The above will scrub array md0 and initiate sector reallocation if needed. You do this while you have redundancy so the bad data can be recovered. Over time, weak sectors get reallocated from the spare bands, and when you do have a failure the probability of a secondary failure is very low over the interval needed for drive replacement.
Presented without comment.