A method and apparatus is disclosed for writing product servo sectors to a
disk of a disk drive to define a plurality of data tracks. The disk drive
comprises the disk and a head actuated over the disk. The disk comprises
a plurality of spiral tracks which are read using the head to synchronize
a write clock and to generate a position error signal (PES) according to
a PES algorithm used to maintain the head along a first servo track while
writing product servo sectors along the first servo track. The PES
algorithm is adjusted to seek the head to a second servo track, and the
head is used to write product servo sectors along the second servo track.