Consider a disk with a sector size of $1024$ bytes, $500$ tracks per surface, $100$ sectors per

track, $6$ single$-$sided platters and a block size of $4096$ bytes. Suppose that a file containing

$1,000,000$ records of $200$ bytes each is to be stored on such a disk and that no record is allowed

to span two blocks.

a$)$ How many records fit onto a block?

b$)$ How many blocks are required to store the entire file? If the file is arranged sequentially

$($contiguously$-$ according to the 'next block concept'$)$ on disk, how many cylinders are needed?

c$)$ How many records of $200$ bytes each can be stored using this disk?

Consider an $4-$drive, $1000GB-$per$-$drive RAID array. What is the available data storage

capacity for each of the RAID levels $0,1,3,4,5,$ and $6?$

Design a backup strategy for a computer system. One option is to use plug$-$in external

disks, which cost SAR$150$ for each $500$ GB drive. Another option is to buy a tape drive for SAR

$5000,$ and $400$ GB tapes for SAR $50$ apiece. A typical backup strategy is to have two sets of

backup media onsite, with backups alternately written on them so in case the system fails while

making a backup, the previous version is still intact. There's also a third set kept offsite, with the

offsite set periodically swapped with an on$-$site set.

a$.$ Assume you have $[$x$]$ TB $(1$ TB $=1000$ GB$)$ of data to back up$.$ How much would a disk

backup system cost?

b$.$ How much would a tape backup system cost for $x$ TB$?$

c$.$ How large would each backup have to be in order for a tape strategy to be less expensive?

d$.$ What kind of backup strategy favors tapes?

Note: For x: Use last two digits of your student number. In case if last two digits are zero then use

the fourth & third last digits.

Important: Show stepwise calculations for all parts. Highlight your answers. Failure to comply

with instruction will result in marks deduction.