Please help with these Operating Systems Questions thank you!!! 1. Calculate the
ID: 3794975 • Letter: P
Question
Please help with these Operating Systems Questions thank you!!!
1. Calculate the total head movements for the following queues using LOOK (head starts at 53)
46, 73, 11, 20, 151, 115, 130, 49
2. Calculate the total head movements for the following queues using FCFS (head starts at 53)
46, 73, 11, 20, 151, 115, 130, 49
3. Calculate the total head movements for the following queues using SSTF (head starts at 53)
46, 73, 11, 20, 151, 115, 130, 49
4. Calculate the total head movements for the following queues using C-LOOK (head starts at 53)
46, 73, 11, 20, 151, 115, 130, 49
5. Calculate the total head movements for the following queues using C-SCAN (head starts at 53, end = 199)
46, 73, 11, 20, 151, 115, 130, 49
6. Linux provides functionality such as flock to set a "flag" that a file is locked for a specific reason. However, by default, every programmer needs to "check" to make sure that a file isn't locked (this is called advisory). Can you think of any other way that would be better (other than remounting using the mand option)?
Explanation / Answer
1. LOOK 182
2. FCFS 295
3. SSTF 182
4. CSCAN 179
5. CLOOK 120
6. The problem with mand is that even root-owned processes, cannot override the lock.so there should be a mechanism of timed mand (mandatory lock)..