OSChapter 7#3DiskSpring 2015

3.Given the following characteristics for a magnetic disk pack with 10 platters yielding 18 recordable surfaces (not using the top and bottom surfaces):

Rotational speed = 13 ms

Transfer rate = 0.15 ms/track

Density per track = 19,000 bytes

Number of records to be stored = 200,000 records

Size of each record = 160 bytes

Block size = 10 logical records

Number of tracks per surface = 500

Find the following:

a.Number of blocks per track

b.Waste per track

c.Number of tracks required to store the entire file

d.Total waste to store the entire file

e.Time to write all of the blocks (Use rotational speed; ignore the time it takes to move to the next track.)

f.Time to write all of the records if theyre not blocked. (Use rotational speed; ignore the time it takes to move to the next track.)

g.Optimal blocking factor to minimize wasted space

h.What would be the answer to (e) if the time it takes to move to the next track were 5 ms?

i.What would be the answer to (f) if the time it takes to move to the next track were 5 ms?