Operating System Unit 5

PART – B (16 MARKS) 
1. Write about the kernel I/O subsystem.
2. Explain the various disk scheduling techniques
3. Write notes about disk management and swap-space management.
4. Suppose that a disk drive has 5000 cylinders, numbered 0 to 4999. The drive is
currently serving a request at cylinder 143, and the previous request was at cylinder 125.
The queue of pending requests, in FIFO order, is
86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130
Starting from the current head position, what is the total distance ((in cylinders) that the
diskarm moves to satisfy all the pending requests, for each of the following disk
scheduling
a. FCFS
b. SSTF
c. SCAN
d. LOOK
e. C-SCAN
5. Compare the performance of C-SCAN and SCAN scheduling, assuming a uniform
distribution of requests. Consider the average response time (the time between the
arrival of a request and the completion of that request’s service), the variation in
response time, and the effective bandwidth. How does performance depend on the
relative sizes of seek time and rotational latency?
5. Explain Disk management in detail
6. Explain the various I/O data transfer schemes
7. Explain the various application I/O interface
8. Write note on (i) Disk attachment
 (ii) Streams
 (iii) Tertiary Storage
9. What is RAID? Explain its various levels 

Operating System Unit 5

PART – A (2 MARKS)

1. What are the registers of I/O Port?
2. What is polling?
3. What are the various I/O data transfer schemes?
4. Is programmed I/O efficient than Interrupt driven I/O? If yes justify your
answer?
5. What are the advantages of DMA?
6. What are the responsibilities of DMA Controller?
7. Define seek time and latency time.
8. What are the characteristics of I/O device?
9. What are the differences between blocking I/O and non-blocking I/O?
10. What are the I/O services provided by Kernel?
11. What is double buffering??
12. Define caching.
13. Define spooling.
14. What are the various disk-scheduling algorithms?
15. What is low-level formatting?
16. What is the use of boot block?
17. What is sector sparing?
18. What is constant angular velocity?
19. What is a stream?
20. What is swap space? What is its use?
21. What is RAID? List out its advantages
22. What is mirroring?
23. Give some examples for tertiary storage
24. Differentiate Scan Vs C-Scan and Look Vs C-Look