<storage, algorithm> A variation of the Scan disk aceess
algorithm for use in a real-time environment where, in
general, requests are served according to Earliest Deadline First. If two requests share the same deadline, they may be
reorganised according to Scan.

A typical example is a video server that retrieves video data
from a hard disk. The playback of a video impose tight
real-time constraints but if the server retrieves data once
every second for each video channel, Scan-EDF can be applied,
reducing the seek overhead.

(1995-11-15)