What do I do if there are bad blocks on my hard drive?

For IDE drives:

If there are bad blocks on the drive, this usually an indication that the drive it going bad. Now a day, all IDE drives come with internal bad block remapping turned on. Check with the manufacturer of the hard drive for warranties on the drive. They sometimes replace the hard drive for you FREE. You can also use diagnostic program from them to run against the drive.

For SCSI drives:

If you drive is a SCSI drive, then you are lucky. SCSI drives have the ability of re-mapping the bad blocks automatically. However, the option might be disabled when the drive is shipped to you.

You can enable this with the following command and settings:

# scsi -f /dev/rsd0c -m 1 -e -P 3

Settings:
AWRE (Auto Write Reallocation Enbld): 1
ARRE (Auto Read Reallocation Enbld): 1

oh… BACKUP YOUR DATA AND REPLACE YOUR THE BAD DRIVE SOON.