A disk drive self-servo writes on a storage disk. Servo bursts are
self-written along a track using a transducer, a position error signal
(PES) indicating repeatable runout due (RRO) for the servo bursts is
determined using a reference pattern, an embedded runout correction (ERC)
value is calculated based on the PES and stored in a corresponding servo
sector, and then the disk drive self-writes other servo bursts.