Disk Scheduling

First-Come, First-Served Requests are serviced in the order they arrive, without regard to the current position of the heads
Shortest-seek-time-first (SSTF) Disk heads are moved the minimum amount possible to satisfy a pending request
Scan Disk heads continuously move in and out servicing requests as they are encountered

First-Come, First-Served Requests are serviced in the order they arrive, without regard to the current position of the heads