N-Step-SCAN

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N-Step-SCAN is a disk scheduling (computing) algorithm to determine the motion of the disk's arm and head in servicing read and write requests. It segments the request queue into subqueues of length N. Breaking the queue into segments of N requests makes service guarentees possible. Subsequent requests entering the request queue won't get pushed into N sized subqueues which are already full by the elevator algorithm. As such, starvation is eliminated and guarentees of serivce within N requests is possible.