Explain the scan disk scheduling algorithm. explain why it is sometimes called the elevator algorithm.

SCAN disk scheduling is the algorithm in which a certain arm of disk rotates in particular direction and serves the requests that arrive from that path. It scans the cylinder's disk in both back and forth direction.

If the arm reaches the bottom of the disk , it automatically stars working in the opposite direction and serves the request in the reverse direction path.As this functioning is similar to the elevator movement ,it is also known as elevator algorithm.