Scan-EDF

Scan-EDF

(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.
References in periodicals archive ?
They include SCAN-EDF [7, 8], SSEDO/SSEDV [9], FD-SCAN [10], SCAN-RT [11], DM-SCAN [12], and Kamel's algorithm [13].
We compare G-SCAN with other representative on-line algorithms, namely, C-SCAN, EDF, SCAN-EDF, and Kamel's algorithm [13] in terms of the average response time, total seek distance, throughput, and deadline miss rate.
EDF and SCAN-EDF result in excessively large average response time for all cases.