Thursday, November 15, 2007

Guide to Operation System Part 4

Disk Optimizations
- First-Come-First-Serve (FCFS)
- Shortest Seek Time First (SSTF)
- SCAN / Circular SCAN (C-SCAN)
- LOOK / Circular LOOK (C-LOOK)


Size of the disk: 0 - 200
Request queue: 90 40 45 120
When disk head is at 50 previously at 20

FCFS: 50 90 40 45 120

SSTF: 50 45 40 90 120

SCAN: 50 90 120 200 45 40
C-SCAN: 50 90 120 200 0 40 45

LOOK: 50 90 120 45 40
C-LOOK: 50 90 120 40 45

Posted by Zack at 2:31 PM