C-SCAN wastes time on the return jump (no service), and always goes to disk end. Can we combine C-SCAN and LOOK?
C-LOOK combines C-SCAN (one direction only) with LOOK (stop at last request), giving uniform wait times without unnecessary travel.
- Move in one direction, service requests
- Stop at last request (don’t go to disk end)
- Jump back to first request
- Continue in same direction (circular)
- Uniform wait times (like C-SCAN)
- No unnecessary travel to disk end (like LOOK)
- Most efficient of the SCAN family
- Default in many modern systems
- Built from: Disk Scheduling, C-SCAN, LOOK
- Related: SCAN
- Contrasts with: C-SCAN (stops at last request vs goes to end)
- Needs to track first and last request
- Most practical for real-world workloads
- Often the default disk scheduler