Question 1(10 Points)

What are the advantages of using a glass substrate for a magnetic disk? 

Question 2 (10 Points)

Explain serpentine recording. 

3.Explain the difference between a simple CAV system and a multiple zone recording system. 

4.What differences between a CD and a DVD account for the larger capacity of the 

DVD? 

5.Consider a single-platter disk with the following parameters:

• Rotation speed: 7200 rpm; 
• Number of tracks on one side of platter: 30,000
• Number of sectors per track: 600; 
• Seek time: one ms for every hundred tracks traversed. 
• Assumption: Let the disk receive a request to access a random sector on a random track and assume the disk head starts at track 0.

 What is the average seek time? 

***Explain your reasoning and show your mathematical calculations on how you derived your answer 

6.Consider a single-platter disk with the following parameters:

• Rotation speed: 7200 rpm; 
• Number of tracks on one side of platter: 30,000
• Number of sectors per track: 600; 
• Seek time: one ms for every hundred tracks traversed. 
• Assumption: Let the disk receive a request to access a random sector on a random track and assume the disk head starts at track 0.

What is the average rotational latency?

***Explain your reasoning and show your mathematical calculations on how you derived your answer 

7.Consider a single-platter disk with the following parameters:

• Rotation speed: 7200 rpm; 
• Number of tracks on one side of platter: 30,000
• Number of sectors per track: 600; 
• Seek time: one ms for every hundred tracks traversed. 
• Assumption: Let the disk receive a request to access a random sector on a random track and assume the disk head starts at track 0.

What is the transfer time for a sector?

***Explain your reasoning and show your mathematical calculations on how you derived your answer 

8.Consider a single-platter disk with the following parameters:

• Rotation speed: 7200 rpm; 
• Number of tracks on one side of platter: 30,000
• Number of sectors per track: 600; 
• Seek time: one ms for every hundred tracks traversed. 
• Assumption: Let the disk receive a request to access a random sector on a random track and assume the disk head starts at track 0.

What is the total average time to satisfy a request? 

***Explain your reasoning and show your mathematical calculations on how you derived your answer 

9.Consider a magnetic disk drive with 8 surfaces, 512 tracks per surface, and 64 sectors per track. 

• Sector size = 1 kB. 
• Average seek time = 8 ms, 
• Track-to-track access time = 1.5 ms, 
• Drive rotates at 3600 rpm. 
• Successive tracks in a cylinder can be read without head movement. 

What is the disk capacity?

**Explain your reasoning and show your mathematical calculations on how you derived your answer 

10.Consider a magnetic disk drive with 8 surfaces, 512 tracks per surface, and 64 sectors per track. 

• Sector size = 1 kB. 
• Average seek time = 8 ms, 
• Track-to-track access time = 1.5 ms, 
• Drive rotates at 3600 rpm. 
• Successive tracks in a cylinder can be read without head movement. 
• What is the average access time?
  **Explain your reasoning and show your mathematical calculations on how you derived your answer  

11. Consider a magnetic disk drive with 8 surfaces, 512 tracks per surface, and 64 sectors per track. 

• Sector size = 1 kB. 
• Average seek time = 8 ms, 
• Track-to-track access time = 1.5 ms, 
• Drive rotates at 3600 rpm. 
• Successive tracks in a cylinder can be read without head movement. 

Assume this file is stored in successive sectors & tracks of successive cylinders, starting at sector 0, track 0, of cylinder i. 

Estimate the time required to transfer a 5-MB file.

**Explain your reasoning and show your mathematical calculations on how you derived your answer 

12. Consider a magnetic disk drive with 8 surfaces, 512 tracks per surface, and 64 sectors per track. 

• Sector size = 1 kB. 
• Average seek time = 8 ms, 
• Track-to-track access time = 1.5 ms, 
• Drive rotates at 3600 rpm. 
• Successive tracks in a cylinder can be read without head movement. 

What is the burst transfer rate? 

**Explain your reasoning and show your mathematical calculations on how you derived your answer