how many surfaces are required

Question

pls xplain the last line of the qs,"records cannot span 2 records" and what effect does it bring to the problem

Comments

3 surfaces.

Answer 1

Cannot span means,1 record cannot be split into two sectors.So in the above example a sector can hold 4000B and hence it can hold only 14 records of 280B [14*280=3920] and 8 bytes will be wasted.So here the 15th record cannot be split.

Is the answer 21 surfaces?

Answer 2

Is ans 5 surfaces

Answer 3

Number of records = 48,44,000
Each Record size = 280 Bytes
Sector Size = 4000 Bytes
number of records/Sector = 4000/280 = 14 records
total sectors required = 4844000/14=346,000
sectors/track = 96
number of tracks required=346,000/96=3605
tracks/surface = 175
number of surfaces required = 20.6=21 surfaces will be required in total

Note: Records can't span two sectors means, a record will completely be stored in single sector