Assume that we are using a hard disk with the following characteristics:

Capacity 30 GB

Average seek time 6 msec

Spindle speed 15,000 rpm

Bytes per sector 512

Sectors per cluster 8

Sectors per track 400.

Assume that we have a file of 20, 000 records. Each record has 64 bytes. Answer the following questions:

1. How much is the average rotational delay?

2. How many records can be stored in one sector?

3. How many clusters are needed for the file?

4. How much is the time for reading one track, including the seek time, the average rotational delay, and the transfer time?

5. Assuming contiguous storage, namely the records are stored in clusters from the same track as long as possible, how much is the total time for reading the whole file?

6. Assuming the minimal transfer unit is one cluster, how much is the time for reading one cluster, including the seek time, the average rotational delay, and the transfer time?

7. Assuming random storage of the records and every record is stored in a different cluster, reading a cluster will include the seek time, the average rotational delay, and the transfer time for that cluster, how much is the total time for reading the whole file?