the second five disks are made from a second sub master having defects 25 finally each of the ten disks has its own unique defects 27 a j respectively which are not part of the repeatable defect table but are found in the drive level final test and added to that drive 39 s defect tables as described above these disk specific defects 27 a j are in addition to the defects 21 imparted by the master and to the defects 23 25 imparted by the respective sub masters in other embodiments that utilize two or more generations of sub masters there will be unique defects in each generation as described herein not only is it necessary to know the ancestry of disks in terms of master and sub master it also is useful to keep track of the order of production of each generation of sub masters and disks made from each sub master for example if a master starts out with n defects it may be observed that after a certain number of sub masters are made n has increased to a larger number all sub masters made after that will have the increased number of defects in contrast the first sub masters made from the.