Q1. Let consider the given page reference string:

1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6.

Determine the page faults which would take place for the given replacement algorithms, supposing five frames? Keep in mind all frames are initially empty, first unique pages will all cost one fault each.

• LRU replacement
• FIFO replacement
• Optimal replacement

Q2. Assume that a disk drive consists of 5,000 cylinders, numbered 0 to 4999. The drive is presently serving a request at cylinder 143 and the prior request was at cylinder 125. The queue of pending requests, in FIFO order, is: 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130.

Beginning from the present head position, determine the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests for each of the given disk scheduling algorithms?

• FCFS
• SSTF
• SCAN
• LOCK
• C-SCAN
• C-LOOK