What is the C-Scan disk scheduling algorithm?

Overview

The C-scan is another disk scheduling algorithm that serves requests generated by the memory management unit.

• In this algorithm, the direction must be considered, that is, towards larger or smaller value.
• This algorithm moves towards the end of disk requests and serves them.
• Once we reach the end of the disk request, it reaches back to 0 during this process as no requests are served.
• Once 0 is reached, the remaining requests are served.

Example

Let’s consider a disk with 200 tracks(0-199), a request queue containing track numbers [82,170,43,140,24,16,190], and the current position of read-write head=50. The requirement is to find the total number of track movements in cylinders.