Operating System(OS) university question bank seventh semester

1.         What is meant by operating systems?
2.         Why is the Operating System viewed as a resource allocator & control program?
3.         What is the kernel?
4.         What are the three main purposes of an operating system?
5.         What are batch systems?
6.         What is the advantage of Multiprogramming?
7.         What are multiprocessor systems & give their advantages?
8.         What are the different types of multiprocessing?
9.      What do you mean by system calls?
10.  What is process control block?
11.  What are schedulers?
12.  What is co-operative process?
13.  What are the use of job queues, ready queues and device queues?
14.  State the advantage of multiprocessor system.
15.  What is the main advantage of multiprogramming?
16.  What is the use of inter process communication.
17.  What is meant by context switch?
18.  What is independent process?
19.  What are the benefits OS co-operating processes?
20.  What is meant by abstract view of system.
21.  What is a process?
22.  What is independent process?
23.  What are the benefits OS co-operating processes?
24.  How can a user program disturb the normal operation of the system?
25.  What is a thread?
26.  What are the benefits of multithreaded programming?
27.  Compare user threads and kernel threads.
28.  What is the use of fork and exec system calls?
29.  Define thread cancellation & target thread.
30.  What are the different ways in which a thread can be cancelled?
31.  What are the various OS components?
32.  How is the protection for memory provided?
33.  What is a process state and mention the various states of a process?
1.         Explain the various types of computer systems.
2.         Explain how protection is provided for the hardware resources by the operating system.
3.         What are the system components of an operating system and explain them?
4.         What are the various process scheduling concepts?
5.         Explain about inter process communication.
6.         List five services provided by an operating system. Explain how each provides convenience to the users. Explain also in which cases it would be impossible for user level programs to provide these services.
7.         Explain the types of system structure in detail.
8.         Explain in detail about virtual machines.
9.      Difference between Hard –Real time systems and Soft-RTS.
10.  Describe the functions of OS and its services.
11.  Explain in detail about Operating System Structures.
12.  Explain the Types of System Calls in detail.
13.  Explain System Programs in detail.
14.  Give an overview about threads.
15.  Explain in detail about the threading issues.
1.         Define CPU scheduling.
2.         What is preemptive and non preemptive scheduling?
3.         What is a Dispatcher?
4.         What is dispatch latency?
5.         What are the various scheduling criteria for CPU scheduling?
6.         Define throughput.
7.         What is turnaround time?
8.         Define race condition.
9.         What is critical section problem?
10.  What are the requirements that a solution to the critical section
           problem must satisfy?
11.  Define entry section and exit section.
12.  Give two hardware instructions and their definitions which can be
           used for implementing mutual exclusion.
13.  What is a semaphore?
14.  Define Critical section.
15.  What are the requirement that must required for Critical section
16.  What are the constraints in Dinning philosopher's algorithm.
17.  What is meant by mutual exclusion.
18.  Declare the structure for monitors.
19.  Declare the structure for Critical section.
20.  List out two methods for synchronous and Asynchronous tasks.
21.  Mention the classical problems to synchronization.
22.  Define deadlock.
23.  What is the sequence in which resources may be utilized?
24.  What are conditions under which a deadlock situation may arise?
25.  What is a resource-allocation graph?
26.  Define request edge and assignment edge.
27.  What are the methods for handling deadlocks?
28.  Define deadlock prevention.
29.  Define deadlock avoidance.
30.  What are a safe state and an unsafe state?
31.  What is banker's algorithm?
32.  What are the conditions necessary to hold for deadlock occur?
33.  Difference between Preemptive and Non-Premptive.
34.  Define Turnaround time, waiting time, response time and throughput.
35.  Queuing diagram for process scheduling.
1.      Write about the various CPU scheduling algorithms.
2.      What is critical section problem and explain two process solutions and multiple process solutions?
3.      Explain what semaphores are, their usage, implementation given to avoid busy waiting and binary semaphores.
4.      Explain about critical regions and monitors
5.      Consider the following set of processes, with the length of the CPU-burst time given in milliseconds:
Process             Burst Time    Priority
P1                         10                3
P2                         1                  1
P3                         2                  3
P4                         1                  4
P5                         5                  2
The processes are assumed to have arrived in the order P1, P2, P3, P4, P5, all at time 0.
a.       Draw four Gantt charts illustrating the execution of these processes using FCFS, SJF, A non preemptive priority
(a smaller priority number implies a higher priority), and RR (quantum = 1) scheduling.
b.      What is the turnaround time of each process for each of the scheduling algorithms in part a?
c.       What is the waiting time of each process for each of the scheduling algorithms in Part a?
d.      Which of the schedules in part a results in the minimal average waiting time (over all processes)?
6.      Explain briefly about Readers/Writers problem in classical synchronization implement using critical section.
7.      What is the use of monitors for resource allocation?
8.      What is the advantage of having different time-quantum sizes at different levels in MFQ-Multilevel Feedback Queue based scheduling.
9.      Consider the following snapshot of a system:
Process         Allocation               Max              Available
AB C D                   A B C D         AB C D
P0      0 0 1 2                   0 0 1 2          15 2 0
P1      1 0 0 0                   1 7 5 0
P2      1 3 5 4                   2 3 5 6
P3      0 6 3 2                   0 6 5 2
P4      0 0 1 4                   0 6 5 6
Answer the following questions using the banker's algorithm:
a.       What is the content of the matrix Need? Is the system in a safe state?
b.      If a request from process P1 arrives for (0, 4, 2, 0), can the request be granted immediately?
10.  Write detailed explanation about Multiprocessor scheduling and Real time scheduling.
11.  Give a detailed description about deadlocks and its
12.  Explain about the methods used to prevent deadlocks.
13.  Discuss the methods of Deadlock detection and Recovery.
1.         Define logical address and physical address.
2.         What is logical address space and physical address space?
3.         What is the main function of the memory-management unit?
4.         Define dynamic loading.
5.         Define dynamic linking.
6.         What are overlays?
7.         Define swapping.
8.         What are the common strategies to select a free hole from a set of available holes?
9.         What do you mean by best fit and worst fit?
10.  What do you mean by first fit?
11.  What is virtual memory?
12.  What is Demand paging?
13.  Define lazy swapper.
14.  What is a pure demand paging?
15.  Define effective access time.
16.  Define secondary memory.
17.  What is the basic approach of page replacement?
18.  What are the various page replacement algorithms used for page
19.  What are the major problems to implement demand paging?
20.  What is a reference string?
21.  What is a Page fault ?
22.  Write about Thrashing. Exactly when it occurs with diagram.
23.  Define TLB? With diagram.
24.  What is meant by External and Internal Fragmentation?
25.  Which algorithm is most effective for Page replacement Policy.
26.  What are the concepts behind in Swapping and Paging.
1.      Explain about contiguous memory allocation.
2.      Give the basic concepts about paging.
3.      Explain about the techniques for structuring the page table.
4.      Explain the basic concepts of segmentation
5.      Given memory partitions of 100KB, 500KB, 200KB, 300KB, and 600KB (in order),how would each of the first-fit, best –fit, worst fit algorithms place processes of 212KB,417KB,112KB, and 426KB(in order). Which algorithm makes the most efficient use of memory?
6.      Explain the various page replacement strategies.
7.      Consider the following page reference string:
1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6.
Ø  How many page faults would occur for the following replacement algorithms, assuming one, two, three, four, five, six, or seven frames? Remember all frames are initially empty, so your first unique pages will all cost one fault each.
         LRU replacement
         FIFO replacement
         Optimal replacement
8.      How many page faults occur for your algorithm for the following reference string, for four page frames?
1, 2, 3, 4, 5, 3, 4, 1, 6, 7, 8, 7, 8, 9, 7, 8, 9, 5, 4, 5, 4, 2.
a.       What is the minimum number of page faults for an optimal page-replacement strategy for the reference string with four page frames?
9.      What is meant by Virtual memory. Give some major benefits which are make applicable.
10.  Discuss briefly about Paging with Segmentation in 32-bit architecture Intel80x86 Structure analysis.
11.  Discuss about
a) Swapping b) Paging c) Segmentation d) TLB hit/miss
1.      List the various file attributes.
2.      What are the various file operations?
3.      What are the various file attributes?
4.      What is the information associated with an open file?
5.      What are the different accessing methods of a file?
6.      What is Directory?
7.      What are the operations that can be performed on a directory?
8.      What are the most common schemes for defining the logical structure of a directory?
9.      Define UFD and MFD.
10.  What is a path name?
11.  What are the various layers of a file system?
12.  What are the structures used in file-system implementation?
13.  What are the functions of virtual file system (VFS)?
14.  What are the advantages of Contiguous allocation?
15.  What are the drawbacks of contiguous allocation of disk space?
16.  What are the advantages of Linked allocation?
17.  What are the disadvantages of linked allocation?
18.  What are the advantages of Indexed allocation?
19.  How can the index blocks be implemented in the indexed
                allocation scheme?
20.  How free-space is managed using bit vector implementation?
21.  What is meant by Consistency Semantics?
22.   What is DNS?
1.      What are files and explain the access methods for files?
2.      Explain the schemes for defining the logical structure of a directory.
3.      Write notes about the protection strategies provided for files
4.      Explain in detail about Linked allocation.
5.      Explain in detail about Indexed allocation.
6.      Write notes about Log-Structured file system.
7.      What are the directory implementation techniques available? Explain in detail.
8.      Explain in detail about various ways of free space management.
9.      Explain in detail about Continuous allocation.
10.  Write notes about file system implementation.
11.  Explain in detail about file system mounting
1.      Define rotational latency and disk bandwidth.
2.      What are the various disk-scheduling algorithms?
3.      What is low-level formatting?
4.      What is the use of boot block?
5.      What is sector sparing?
6.      Define Seek time and Bandwidth.
7.Explain LDAP.
8.What is polling?
9.What is an interrupt?
10.  What is DMA?
11.  List the applications of I/O Interface.
12.  Distinguish between blocking and non-blocking I/O.
13.  What do you meant by double buffering?
14.  Define caching.
15.  Define spooling.
16.  What are streams.
17.  Distinguish between a STREAMS driver and a STREAMS module.
18.  What is a low level formatting?
19.  Define boot block.
20.  What is RAID?
21.  Distinguish bit-level striping and block-level striping.
22.  List the levels of RAID.
23.  Distinguish host attached storage and network attached storage.
1.      Write about the kernel I/O subsystem.
2.      Explain the various disk scheduling techniques
3.      Write notes about disk 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 disk arm moves to satisfy all the pending requests, for each of the following disk scheduling
5.      What is meant by RAID levels? Which level is used for what purpose?
6.      Analyze Disk arm movement reduced when/which one is effective for given
Queue=87, 170, 40, 150, 36, 72, 66, 15
Starting point of current head is 60.
7.      Explain in detail about stable storage and tertiary storage implementation.
8.      Write notes on disk attachment.
9.      Explain about swap-space management.
10.  How does DMA increase system concurrency? How does it complicate the hardware design?
11.  Write notes on STREAMS.
Next Post »