Problem $1$

Explain in detail how a Magnetic Hard Disk Drive works.

For the following two problems, apply the SSTF$,$ SCAN, C$-$SCAN, LOOK and C$-$Look algorithms for the following and identify the order that the requests will be serviced. For each calculate the total head movement. For each draw a graph representing the movement of the head.

Problem $2$

A system has the following Block I$/$O request queue $(99,20,60,65,10,50,69,81).$ The read$-$write head is currently at $54.$ The total number of block on the disk are $100(0-99).$

Problem $3$

A system has the following Block I$/$O request queue $(35,10,150,80,90,55,45,25,30).$ The read$-$write head is currently at $91.$ The total number of block on the disk are $200(0-199).$