A method, computer readable medium, apparatus and RAID controller for performing
nondestructive write testing is disclosed. For data storage devices divided into
sectors, the present invention performs nondestructive write testing by writing
data to the sectors, reading data written to the sectors, and comparing the data
written to the data read to detect errors. To increase efficiency, sectors previously
written by a host or other computer are tracked, allowing sectors not previously
written to be tested without saving and restoring data in the sectors. To locate
the sectors written to by the host computer, write indicators such as a sector
written indicator, a sector stripe written indicator, and a stripe written indicator
are maintained. Upon detecting a defective sector, a new sector is allocated, and
the defective sector is replaced by the allocated sector.
