Question

    Which I/O scheduling algorithm is most suitable for

    minimizing seek time in hard drives?
    A First-Come-First-Serve (FCFS) Correct Answer Incorrect Answer
    B Shortest Seek Time First (SSTF) Correct Answer Incorrect Answer
    C SCAN Correct Answer Incorrect Answer
    D LOOK Correct Answer Incorrect Answer
    E Circular SCAN (C-SCAN) Correct Answer Incorrect Answer

    Solution

    The Shortest Seek Time First (SSTF) algorithm prioritizes requests based on proximity to the current position of the disk head, thereby minimizing seek time. By processing the closest request first, it reduces the movement of the read/write head, improving efficiency and speed. SSTF is particularly effective when disk requests are concentrated around specific areas. However, a downside is the risk of starvation , where requests far from the current head position may be delayed indefinitely. Why Other Options Are Incorrect:

    • Option A: FCFS processes requests in the order they arrive, which may lead to excessive head movement and higher seek times.
    • Option C: SCAN moves the disk head in one direction, servicing requests along the way, which reduces starvation but may involve more movement than SSTF.
    • Option D: LOOK is similar to SCAN but stops at the last request in the direction of motion. It still involves more head movement compared to SSTF.
    • Option E: C-SCAN ensures uniform wait times but does not minimize seek time as effectively as SSTF.

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