shortest seek time first sstf - TarisMajor/5143-OpSystems GitHub Wiki

Shortest Seek Time First (SSTF) is a disk scheduling algorithm that selects the disk I/O request that is closest to the current disk head position. By minimizing the seek time—the time it takes for the disk arm to move to the required track—SSTF can improve overall disk performance compared to the First-Come, First-Served (FCFS) approach.

1. Proximity-Based Selection: SSTF prioritizes requests based on their proximity to the current position of the disk head. The request with the shortest seek time is serviced next.
2. Dynamic Order: Unlike FCFS, the order in which requests are serviced can change dynamically as new requests arrive.

1. Reduced Seek Time: By always servicing the closest request, SSTF minimizes the seek time, leading to faster overall disk performance.
2. Improved Throughput: The reduction in seek time generally results in higher throughput, meaning more I/O operations can be completed in a given time period.

1. Starvation: Requests that are far from the current disk head position can experience indefinite delays if closer requests keep arriving. This can lead to starvation of some requests.
2. Complexity: Implementing SSTF requires keeping track of all pending requests and dynamically calculating seek times, which adds complexity to the scheduling algorithm.

1. Systems with High I/O Demand: Suitable for environments where high disk throughput is required, such as database servers and large-scale data processing systems.
2. Real-Time Systems: Can be beneficial in systems where minimizing the average response time is crucial, provided measures are in place to prevent starvation.

• Operating System Concepts by Abraham Silberschatz, Peter B. Galvin, and Greg Gagne
• Disk Scheduling Algorithms - GeeksforGeeks
• Modern Operating Systems by Andrew S. Tanenbaum
• Wikipedia - Disk Scheduling
• ChatGPT