Ever wondered how your operating system decides which I/O request to serve next when multiple processes need to read/write from a hard disk? Enter — a performance-boosted version of the classic SCAN (elevator) algorithm.
🔍 SCAN moves the disk head from one end of the disk to the other, servicing requests in its path — like an elevator going up and down a building. d.cscan.con
⚡ “DC” stands for Directional Continuity (or sometimes “Disk C-SCAN” variant with dynamic tuning). In DC-SCAN, after reaching the end, the head immediately jumps back to the start without servicing requests on the return trip — then resumes scanning again. This ensures fairness and reduces variance in response times. Ever wondered how your operating system decides which