Please Help with these Operating Systems questions thank you!

1. How is X-RAID or Hybrid RAID different than regular RAID levels?

2.Make a list of six security concerns for a banks computer system. Foreach item on your list, state whether this concern relates to physical,human, or operating-system security.

3. How would you protect against a port scan?

4. Calculate the total head movements for the following queues using:

FCFS SSTF SCAN C-SCAN LOOK C-LOOK

a. 76, 95, 73, 12, 150, 20, 4, 22, 47, 33, 100 (start = 50, end = 199)

b. 13, 17, 146, 23, 36, 120, 33, 77, 41, 97, 89 (start = 180, end = 199)

5. Compare symmetric and asymmetric encryption schemes, and discuss the circumstances under which you would use each.

6. Describe in your own words the following RAID levels (and state the least number of drives needed to use it):

a. RAID0 b. RAID1 c. RAID5