Perform the same type of analysis as that of Table 11.2 for the following sequence of disk track requests: 27, 129, 110, 186, 147, 41, 10, 64, 120. Assume that the disk head is initially positioned over track 100 and is moving in the direction of decreasing track number.
Do the same analysis but now assume that the disk head is moving in ther direction of increasing track number.
| FIFO | FIFO | SCAN | C-SCAN | ||||
| (Starting at Track 100) | (Starting at Track 100) | Increasing track # | Increasing track # | ||||
| Next Track Accessed | # of Tracks Traversed | Next Track Accessed | # of Tracks Traversed | Next Track Accessed | # of Tracks Traversed | Next Track Accessed | # of Tracks Traversed |
| 55 | 45 | 90 | 10 | 150 | 50 | 150 | 50 |
| 58 | 3 | 58 | 32 | 160 | 10 | 160 | 10 |
| 39 | 19 | 55 | 3 | 184 | 24 | 184 | 24 |
| 18 | 21 | 39 | 16 | 90 | 94 | 18 | 166 |
| 90 | 72 | 38 | 1 | 58 | 32 | 38 | 20 |
| 160 | 70 | 18 | 20 | 55 | 3 | 39 | 1 |
| 150 | 10 | 150 | 132 | 39 | 16 | 55 | 16 |
| 38 | 112 | 160 | 10 | 38 | 1 | 58 | 3 |
| 184 | 146 | 184 | 24 | 18 | 20 | 90 | 32 |
| Avg. Seek Time | 55.3 | Avg. Seek Time | 27.6 | Avg. Seek Time | 27.8 | Avg. Seek Time | 35.8 |