Question $1-($based on $11\mathrm{.}12$ and $11\mathrm{.}16,$ p$\mathrm{.}527)$

$[20]$

$($Ex$011\mathrm{.}12,$ p$\mathrm{.}526)$: Suppose that a disk drive has $4000$ cylinders, numbered $0$ to $3,999.$ The drive is currently serving a request at cylinder $1,150,$ and the previous request was at cylinder $1,805.$ The queue of pending requests, in FIFO order, is:

$2,000$;$1,212$;$2,396$;$2,800$;$544$;$1,618$;$346$;$1,523$;$3,965$;$3,681$

Starting from the current head position, what is the total distance $($in cylinders$)$ that the disk arm moves to satisfy all the pending requests for each of the following disk$-$scheduling algorithms?

a$.$ FCFS

b$.$ SCAN

c$.$ C$-$SCAN

$($Ex$011\mathrm{.}16,$ p$\mathrm{.}527)$: Assume that you have a configuration comprising disks organized as RAID level $1$ and RAID level $5$ disks. Assume that the system has flexibility in deciding which disk organization to use for storing a particular file. Which files should be stored in the RAID level $1$ disks and which in the RAID level $5$ disks in order to optimize performance?