A bad sector is remapped or reallocated to good SPARE block and this INFORMATION is stored in the internal table on the HARD disk drive. The bad blocks are identified during the media test of the HDD as well as during various types of read write operations performed during the I/O tests. APART from the new generation of HDD comes with a technology called BGMS (background media scan) which continuously scans the HDD media for defects and maps them when the drive is IDLE (this is performed after the HDD is attached to the system).

A bad sector is remapped or reallocated to good spare block and this information is stored in the internal table on the hard disk drive. The bad blocks are identified during the media test of the HDD as well as during various types of read write operations performed during the I/O tests. Apart from the new generation of HDD comes with a technology called BGMS (background media scan) which continuously scans the HDD media for defects and maps them when the drive is idle (this is performed after the HDD is attached to the system).