LLD - Design — Elevator SystemWhat is the primary goal of the SCAN disk scheduling algorithm?ATo randomly select requests to service nextBTo reduce the total seek time by moving the head in one direction servicing all requestsCTo service requests in the order they arrive without reorderingDTo always service the closest request regardless of directionCheck Answer
Step-by-Step SolutionSolution:Step 1: Understand SCAN algorithm behaviorSCAN moves the disk head in one direction, servicing all requests until it reaches the end.Step 2: Identify the goal of SCANThis approach reduces seek time by minimizing back-and-forth movement.Final Answer:To reduce the total seek time by moving the head in one direction servicing all requests -> Option BQuick Check:SCAN goal = reduce seek time by directional scan [OK]Quick Trick: SCAN moves head in one direction servicing all requests [OK]Common Mistakes:MISTAKESThinking SCAN services requests randomlyConfusing SCAN with FCFS (first-come, first-served)Assuming SCAN always services closest request first
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