I have a western digital 2.0TB Black hard drive that was returning a SMART error of "9 Currently unreadable (pending) sectors". This probably means the drive is on it's way out, but it was passing long smart tests ok, and it's in a raid so I've decided to try and fix it. I've read that writing to the drive can force the hard drive to reallocate those sectors, so I gave it a try with the dd command:
dd if=/dev/zero of=/dev/sdc
Before and after smart data:
# before 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 9 # after 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0
And then I've partitioned the drive and have been using it without issues now for a few weeks. Time will tell if this ends up working I suppose.