Operating System Case Question

1. I/O Management: Disk Arm Scheduling & RAID

a. It is known that a disk drive has 256 cylinders, with cylinder numbers starting from 0 and ending at 255. The position of the needle on the disk drive currently stops at 128. It is also known that the needle is always to the cylinder with the same number. smaller first. The order of the positions visited sequentially is: 254, 64, 32, 100, 50, 70.

From the 3 choices of algorithms below, which one is the best algorithm? Make each image and determine the seek time. i. SCAN ii. C-SCAN iii. FIFO

b. The X company has 300 branches throughout the country, therefore the company decided to create a RAID system on the X company database system. You are asked to analyze: i. What is the difference between mirroring, parallel access, and independent access? ii. If a company can only have a maximum of 3 disks, and information has to be spread across all those disks, what RAID would you recommend?

Note: - Please answer in the proper format and rightfully. - Please answer in soft-copy format.