Patent ID: 8654619

Claim:
A disk drive comprising: a rotatable disk having a user area including a first sector, and a spare area including a second sector, and configured to store a relocation list; a head actuated over the disk and configured to read from the disk and write to the disk; and a controller configured to: receive a write command to write first data to the first sector; determine that the first data includes an amount of data less than a storage capacity of the first sector; read second data in the first sector using the head; determine that there is a read error when reading the second data in the first sector; temporarily relocate the first sector to the second sector; provide a temporary relocation entry in the relocation list; maintain the second data in the first sector; and perform a test on the first sector to determine whether to copy the first data to the first sector, and remove the temporary relocation entry in the relocation list, or permanently relocate the first sector to the second sector.