A disk drive includes a rotatable data storage disk, a transducer, an
actuator, and a controller. The transducer is configured to read and
write data on the disk. The actuator is configured to position the
transducer relative to defined portions of the disk. The controller is
configured to write a predetermined magnetic polarity pattern on a buffer
portion of the disk to erase data thereon. The controller also determines
whether the disk drive has reached a threshold operating temperature, and
to selectively direct data from a host device, which is addressed for an
associated original block address on the disk, to be written to the
buffer portion of the disk when the disk drive has not reached the
threshold operating temperature. The controller later copies the data
from the buffer portion of the disk to the original block address on the
disk and then erases the data from the buffer portion of the disk.