A method and apparatus for compensating for non-linearities due to pivot
bearing friction when determining embedded runout correction values
during partial self-servo write of a disk drive is disclosed. In one
embodiment, the disk drive includes a disk surface having a track written
thereon and the track has some written-in runout. The written-in runout
that is associated with high-frequencies is determined using a first
technique. The written-in runout for the track that is associated with
low frequencies is determined using a second technique. Results from the
two techniques are combined in order to determine embedded runout
correction values for the track when partial self-servo writing, in order
to reduce error propagation when writing additional tracks.