In a novel method for controlling a disk apparatus having an interface,
command storage, and data storage, one or more commands are received from
an external apparatus via the interface, and the one or more commands are
held in the command storage. A command to be next executed is selected
from among the one or more commands and dispatched for execution. It is
determined whether an error relating to accessing the data storage has
arisen during execution of the selected command. If so, the selected
command is restored to the command storage. A subsequent command to be
next executed may then be selected. In one described embodiment, an
estimated seek time for the selected command is determined, and it is
judged that an error has arisen if actual seek time of the selected
command exceeds the estimated seek time.
