Question

Consider a disk that is scheduled using the Shortest Seek First (SSF) policy. At time t, let the disk have the following requests in its queue: Request Cylinder R1 45 R2 39 R3 49 R4 52 R5 69 R6 35 R7 3 R8 66. Assume that the disk head is in cylinder 43 at time t and no other requests arrive until all of the above requests are processed. Determine the schedule of processing for the above set of requests. Based on the processing schedule, identify the TRUE statement among the following, with respect to the relative order of processing the various requests.

a. R6 is processed after R4
b. R8 is processed before R6
c. R4 is processed after R8
d. R5 is processed before R4

Answer 1

Option A

Step-by-step explanation:

Considering that the disk head is at cylinder 43, the next number it will detect will be 45 then 49 followed by 52 as it moves ahead. It will then move back to 39 then 35 and forward to 66 then 69 and finally 3

The order will be as follows

R2(45) -- R3(49) -- R4(52) -- R1(39) -- R6(35) --R8(66) -- R5(69)--R7(3)

Therefore, option A is correct