Final answer:
The question involves the scan-EDF disk scheduling algorithm and whether any requests will miss their deadlines considering an average service time of 6 ms and the current time of 15 ms. The requests should be serviced in the order of their deadlines; however, without additional information on the starting position of the disk head and the cylinder layout, it's impossible to determine definitively whether a deadline will be missed.
Step-by-step explanation:
The student's question pertains to the scan-EDF (Earliest Deadline First) scheduling algorithm used in disk scheduling. In scan-EDF, requests are grouped by the nearest deadlines and those groups are then served based on disk head movement in a single direction until there are no requests in that direction, after which the direction is reversed. Here, we are given a set of disk requests with deadlines and cylinder numbers and asked if any deadlines will be missed if each request takes an average of 6 milliseconds to service and the current time is 15 milliseconds.
- First, sort the requests by their deadlines: (32, 300), (34, 310), (36, 500), (40, 210).
- Then, determine the time needed to service each request by considering the head movement and service time.
- Starting from the current time (15 msec), calculate if the service time for each request, when added to the current time, exceeds the deadline.
If the calculated time exceeds the deadline for any request, that request's deadline is missed. However, given the lack of information about the initial position of the disk head and the distance between cylinders, a definitive answer on whether deadlines are missed cannot be provided.