Operating system

a. Suppose that a disk drive has 10,000 cylinders, numbered 0 to 9999. The driver is currently serving a request ar cylinder 1400. The queue of pending requests is, in the order received: 100, 1200, 900, 8000, 8100, 100, 8200, 1000, 4200 Starting from the current head position, what is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests for the following scheduling algorithms. (For the algorithms in which the head is in constant motion, indicate the direction in which you assume it is moving initially.) (i) FCFS (ii) SSTF (iii) SCAN (iv) C-LOOK * b. Explain the purpose of the open) and close0 operations [12 marks] 3 marks] 4 marks] c. Briefly explain any two types of virtualization * d. Allocation/replacement of frames among different processes can either be local or global. What do you understand by this? What could be a possible effect of using the later(global replacement) 6 marks a. Briefly explain any 3 ways by which domain switching is accomplished in UNIX based Operating System [9 marks] 15 marks] b. Write extensively on Access Matrix as it relates to protection c. How does hardware acceleration for virtualization affects the the processing speed of processes on Virtual Machine? d. Briefly differentiate between absolute and relative pathname. Give an example in each cases 4 e. In one sentence, briefly explain why SSDs often use an FCFS disk-scheduling algorithm. 5 marks] 12 marks] ai. TLB was introduced in paging to avoid the two memory accesses. What do you understand by the term "two memory access" in this context. aii Building on your understanding in (a), explain how TL.B works with paging memory allocation. (A well label diagram might suffice ) Expected keywords: TLB miss, TLB hit, Page table, physical address, logical address. b. Explain the "principle of least privileged" as it relates to protection c. Briefly explain the advantages of using two-level directory structure over a single-level structure [4 marks] d. Explain disk formating e. In one sentence, differentiate between volume and raw disk partition. [4 marks] [6 marks] [4 marks] [5 marks] 12 marks]