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10CS53:Operating Systems Question Bank UNIT 1: INTRODUCTION TO OPERATING SYSTEMS & THEIR CLASSIFICATION Objective: The main objective of this chapter is to study the Operating system basics & Classifications. 1. 2. 3. 4. 5. 6. 7. 8. 9. What are the 3 main purposes of an Operating System? Explain the concept of virtual machines. Explain the distinguishing features of i) Real time system ii) Multiprocessor system What is the purpose of command interpreter? Why is it usually separate from the Kernel? What is an Operating System? Explain considering different possible views What is operating system? What are functions of operating system? What are multiprocessor systems? Give advantages. What is the main difficulty that a programmer must overcome in writing an operating system for real time environment? Define spooling and the need for it. Explain its working with necessary diagrams. 10. Explain the following terms and their working with diagram a) Buffering b) Spooling c) Time sharing d) Distributed system e) Real-time 11. Compare tightly coupled systems with loosely coupled systems. 5 5* 6* 6* 6* 6* 6 6 6* 6x5* 6* 12. Describe differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantages of multiprocessor systems? 13. Explain distinguished features of i) Time-sharing system ii) Parallel processing 14. Write a brief note on different operating system structures 10* 8* 8* 15. Explain different sub components of an operating system. 8* 16. Bring out the requirements of i) Real time operating systems (ii) Distributed operating systems 17. What is an Operating System? Justify the statement “Operating System can be viewed as a government, resource allocator and a control program”. 18. Define essential properties of the following types of Operating system: i) Batch operating system ii) Interactive operating system ii) Time sharing operating system iv) Real time operating system v) Distributed operating system 19. Distinguish among the following terminologies associated with the operating system and explain each of them in detail. i) Multiprogramming systems. ii) Multitasking systems. iii) Multiprocessor systems. 20. Define Operating systems. Discuss its role with user and view points 21. Define a virtual machine (VM). With a neat diagram, explain the working of a VM. What are the benefits of a VM? 8* PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 8* 10* 12* CS / IS 6 9 10CS53 - 1 22. Explain the 'graceful degradation' and 'fault tolerant' in a multiprocessor system. 23. Write and explain the sequence of system calls for copying a file to another (new) file. 24. What are system calls? Explain the different categories of the system calls. . 6 5 10 UNIT 2: OPERATING SYSTEM STRUCTURES Objective: The Operating System provides certain services to programs and to the users of those programs in order to make their tasks easier. The services differ from the operating system to another, but we identify and explore some common classes of these services. 1. 2. 3. 4. 5. 6. List out services provided by the Operating Systems? What are client server systems & Peer-to-Peer systems? What is the purpose of the system calls & system programs? Explain the layered approach of the operating system Write short notes on operating system components. Describe process states with the help of process transition diagram What is the main difficulty that a programmer must overcome in writing an operating 7. system for real time environment? 8. Give difference between Job-scheduling & CPU-scheduling. 9. Define spooling and the need for it. Explain its working with necessary diagrams. 4* 5 5* 5 5* 6* 6 10. What is the meaning of overlapped CPU and I/O operation? Explain. 6* Distinguish between : i) Process and Program ii) Multiprogramming and multiprocessing iii) Job scheduling and CPU scheduling 12. What are system calls? What are categories of system calls? 6* 6 6* 11. 6* 13. What are the five major activities of an operating system in regard to file management 6 14. What are the five major activities of an operating system in regard to process management? 15. What are the three major activities of an operating system in regard memory management 16. What are the three major activities of an operating system in regard to secondary storage management 17. Explain the functions of the following: i) System Calls ii) System programs iii) Command Interpreter 18. Explain the layered approach to the structuring of an operating system along with the relevant diagram 19. List out and explain briefly the various services that the operating system provides to programs and users 20. Explain the different system components of an operating system. 6 6 6 6* 8* 10* 21. What is the purpose of command interpreter? Why is it usually separate from kernel? 12 6 UNIT 3: PROCESS, INTER PROCESS COMMUNICATION, THREADS & CPU SCHEDULING PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem CS / IS 10CS53 - 2 Objective: This Chapter will give details of how OS is responsible for Creation and deletion of both users And system processes, the scheduling of processes, providing mechanisms for synchronization communication and deadlock handling for processes. Also you can study how to improve both utilization of CPU and speed of computer's Response for the users, different scheduling algorithms. 1. 2. 3. 4. 5. 6. 7. 8. What are different differences between user level threads & Kernel supported threads? What is Scheduler? What is a dispatcher? Give the information that is kept in process control block What are threads? What is co-operating process? Write short note on CPU scheduling criteria. Explain different types of CPU Schedulers. Differentiate the following with examples i) Preemptive and non preemptive scheduling ii) I/O bound and CPU bound iii)Scheduler and dispatcher 9. Differentiate Pre-emptive and Non-preemptive scheduling giving the application of each of them 10. What is the criterion used to select the time quantum in case of round-robin scheduling algorithm? Explain it with a suitable example. 11. Explain multilevel feedback queue scheduling with example. 12. Differentiate between a process and a program. Describe the life cycle of a process 13. What is a process? Explain the process status diagram. 14. Write short note on algorithm evaluation 15. Describe the process states with the help of process transition diagram 16. Explain the concept of ‘process’. also describe the contents of a process control block(PCB) 17. What resources are used when a thread is created? How do they differ from those used when a process is created? 18. Define the actions taken by a kernel to context switch: a. among threads b. among processes 19. What are co-operating processes? Describe the mechanism of inter process communication using shared memory in a producer-consumer problem 20. What is co-operating process? Explain. 21. What is interprocess communication? Explain 22. Explain process states with a diagram. What is the need for a context switch? 23. Explain the role of long term scheduler, medium term scheduler and short tem scheduler in O.S 24. Explain the PCB in detail 25. Explain how process are created and terminated. 26. Discuss the different types of schedulers, giving the advantage and limitation of each. 27. Describe interprocess communication with regard to direct communication and indirect communication. 28. For the following set of process find the average waiting time using Gantt chart for i> SJF ii> Priority scheduling process Burst time Priority p1 5 5 p2 3 4 p3 8 3 p4 2 1 p5 1 2 The process has arrived in the order p2, p1, p4, p3 and p5. PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 4* 6 4* 4 5 5* 5* 5x3* CS / IS 6* 6 6* 6* 6* 6* 6* 6* 6 6 6* 7* 7* 8* 8* 8 8 8* 8* 8* 10CS53 - 3 29. What is the difference between a preemptive and non-preemptive scheduling algorithms? Explain FCFS scheduling algorithm. Find the average turnaround time and average waiting time for the processes given in the table below. Process CPU burst time(in ms) P1 24 P2 3 P3 3 30. Consider the following data with burst time given in milliseconds: i> SJF ii> Priority scheduling process Burst time Priority p1 10 3 p2 1 1 p3 2 3 p4 1 4 p5 5 2 The process has arrived in the order p1, p2, p3, p4, p5 all at time 0. a. Draw Gantt charts for the execution of these processes using FCFS, SJF, a nonpreemptive priority and RR (quantum=1) scheduling. b. What is the turnaround time and waiting time of each process for each of the scheduling algorithm. 31. What 2 advantages do threads have over multiple processes? What major disadvantages do they have? Suggest one application that would benefit from the use of threads. 32. What do you mean by process and process state? Give the state diagram corresponding to process states and explain 33. Suppose the following jobs arrive for processing at the times indicated, each job will run the listed amount of time. Job arrival time burst time 1 0.0 8 2 0.4 4 3 1.0 1 i) Give a Gantt chart illustrating the execution of these jobs using the non preemptive FCFS and SJF scheduling algorithms. ii) what is turn around time and wait time of each job for the above algorithms? iii) compute average turn around time if the CPU is left idle for the first 1 unit and then SJF scheduling is used.(job q and job 2 will wait during this time)` 34. Consider the following set of processes with their arrival and burst times as shown Process A.T B.T P0 0 10HR P1 0 05HR P2 1 02HR P3 2 01HR Compute the turn around time and waiting time of each job using the following scheduling algorithms. i) FCFS ii) S.J.F iii) Round-Robin ( choose time quantum=1) 35. For the following set of processes, find the average waiting time & average turn around time using GANTT Chart for I > FCA II> SJF preemptive. III> SJF non-preemptive. Process Arrival time (in sec) Burst Time(in sec) P1 0 4 PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 8* 10* 10 10* 10* 10* 10* CS / IS 10CS53 - 4 P2 P3 P4 1 2 3 2 5 4 36. What are threads ? how do they differ from a process? Explain the difference in process level switching and thread level switching 37. Distinguish between symmetric and asymmetric communication between processes. 38. Define CPU utilization, throughput, and turnaround time, waiting time and response time 39. Explain the different types of scheduling algorithms. 40. Five batch jobs A,B,C,D and E arrive at a computer centre at almost at the same time. They have estimated running times of 10,6,2,4 and 8 minutes. Their priorities are 3,5,2,1 and 4 respectively, with 5 being the highest priority. For each of the following scheduling algorithm determine the turn around time of each process and waiting time of each process. Ignore process switching overhead. Mention which algorithm results in minimal average waiting time. i) Round Robin ii) Priority scheduling iii) First come first served iv) Shortest job first. For case i) assume that system is multiprocessing and each job gets its fair share of the CPU.(time quantum 2 minutes0. For cases (ii),(iii) and (iv) assume that only one job runs at a time, until it finishes. All jobs are completely CPU bound. 41. Compare virtual machine and non virtual machine 42. Discuss three common ways of establishing relationship between the user thread and kernel thread 43. Consider the following set of rocesses, with the len of CPU burst in milliseconds. Process PI P2 P3 P4 P5 Arrival time 00 02 03 06 30 Burst time 10 12 14 16 05 Draw a Gantt chart that illustrates the execution of these processes using the preemptive shortest job first (SJF) algorithm. Hence find the average waiting time. Draw a Gantt chart that illustrate the execution of these processes using preemptive priority scheduling algorithm. Given priority of each process is PI = 4, P2=3, P3::=5, P4= 1 and P5= 1. Also find the average waiting time 10* 10* 10 10* 12* 6 6 10 UNIT 4 & 5: PROCESS SYNCRHONISATION AND DEADLOCKS Objective: Upon completion of this chapter you will be able to define how data consistency is maintained, Study of Semaphores, use and its implementation, Classical problems of synchronization, Deadlock and methods for handling deadlocks. 1. What is critical section? What requirement should be satisfied for a solution to the critical section problem? 2. What are classical problems of synchronization? 3. Explain the terms critical section and mutual exclusion. 4. Write a note on ‘safe state’ 5. Explain starvation. Differentiate deadlock and starvation. 6. What is semaphore? Explain. 7. What are semaphores? Explain how it can be used to implement mutual exclusion 8. Define resource allocation graph with an example and show how it can be used for dead PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem CS / IS 4* 4* 4* 4* 4 5* 5* 5* 10CS53 - 5 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. lock link detection What are monitors? Explain. Explain the critical section problem Explain the readers/writers problem What are the necessary conditions for deadlock to occur? Explain the resource allocation graph What is the term busy waiting? What other kinds of waiting are there in an OS? Can busy waiting be avoided altogether? Explain. Suggest the methods for deadlock recovery What is a semaphore and a counting semaphore? Explain how a semaphore can be used so that statement S1 of process P1 is always executed first, and only then statement S2 of process P2 is executed. What is a deadlock? Explain how resource allocation graph can be used to check for deadlock in a system. Write an algorithm to implement critical section problem for multiple processes What do you mean by a binary semaphore and a counting semaphore? Along with the necessary 'C'-struct, explain the implementation of wait( ) and signal( ) semaphore operations Explain the synchronizing protocol of a classical readers/writers problem. Write a symbolic program code to implement any one of the above protocol. What are called as co-operating processes? Explain the necessity of mutual exclusion with an example. Explain the methods for deadlock prevention What is a semaphore? Explain the role of semaphore in solving mutual exclusion problem Given 3 processes A,B and C, three resources x,y and z and following events, i) A requests x ii) A requests y iii) B requests y iv) B requests z v) C requests z vi) C requests x vii) C requests y Assume that requested resources should always be allocated to the request process if it is available. Draw the resource allocation graph for the sequences. And also mention whether it is a deadlock? If it is, how to recover the deadlock. 25. 26. 27. 28. 29. 30. 31. Explain the deadlock avoidance algorithm What is deadlock? Explain the necessary conditions for its occurrence. Give a scheme for detecting and recovering deadlock What is critical section problem? Write a solution to n process critical section problem. Define deadlock. List and elaborate the necessary condition for deadlock to occur. What is Bankers algorithm? Explain. With the necessary syntax, describe the term monitor. Explain the solution to the classical dining philosopher's problem, using monitor. 32. Defme test and set instruction and implement mutual exclusion, using test and set 33. Describe the Bounded - buffer problem and give a solution for the same using semaphores. Write the structure of producer and consumer processes. 34. Define the algorithms TestAndSet( ) and swap( ). Show that they satisfy mutual exclusion. 35. What is critical section problem and what are the requirements that need to be satisfied by any solution to critical section problem? Give a solution to a 2 process critical section problem. 36. Write and explain Banker’s algorithm for deadlock avoidance PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem CS / IS 5* 5* 6 6 6 6 6* 7* 8* 8* 10 8* 8* 8* 8* 8* 8 10* 10* 10* 10* 10* 10 5 8 8 10* 10* 10CS53 - 6 37. What is critical section problem? Give a software solution to critical section problem in multiple processes. 38. What is the difference between deadlock prevention and deadlock avoidance methods of dealing with a dead lock problem? Explain the different approaches towards a dead lock detection problem when i) there is a single instance of a resource type ii) Multiple instances of a resource type 39. Write and explain deadlock detection algorithm and explain how it differs from Banker’s algorithm. 40. What is deadlock? Explain the various methods for dealing with deadlock problem 41. Mention any hardware machine instruction you know of which can be used to implement the ‘wait-s’ function for binary semaphore –S. Demonstrate how the specific instruction could be used to implement the desired function. State the disadvantages of the above method and suggest a more efficient method of implementing semaphore operations. 42. Explain banker’s algorithm using the example given below A system has 5 processes, p1,p2,p3,p4 and p5.There are 3 types of resources r1,r2 and r3.there are 10 instances of r1, 5 instances of r2 and 7 instances of r3. At time t0, the situation is as follows; Process P1 P2 P3 P4 P5 allocation of r1 r2 r3 0 1 0 2 0 0 3 0 2 2 1 1 0 0 2 P0 P1 P2 P3 P4 P5 allocation A 0 1 1 0 0 B 0 0 3 6 0 Max C 1 0 5 3 1 12* 12* 12* 12* 12* maximum requirement of r1 r2 r3 7 5 3 3 2 2 9 0 2 2 2 2 4 3 3 Is the system in a safe state at time t0? Suppose now a time t1, process p2 requests one additional instance of resource type r1 and 2 instances of resource type r3, supposing the request if granted will the system be in a safe state? 43. Consider the following snapshot of a system Process 12* D 2 0 4 2 4 A 0 1 2 0 0 B 0 7 3 6 6 10 Available A B C D 1 5 2 0 C 1 5 5 5 5 D 2 0 6 2 6 Answer the following questions using Bankers Algorithm 1.What is the content of array node 2.Is the system in a safe state ?? 3.If a request from process P1 arrives for (0,4,2,0) can the request be immediately granted ?? 44. Explain with an example how resource allocation graph is used to describe the deadlock PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem CS / IS 6 10CS53 - 7 UNIT 6: STORAGE MANAGEMENT Objective: In this unit you will be able to define How memory can be shared and managed so that CPU can be utilized in a better way and system response time is improved, how multiprogramming is achieved & how different processes in an OS are protected and controlled access can be provided to programs and data. Here we includes different file operations and secondary storage management. 1. What is storage hierarchy? 2. What are file protection methods? 3. Differentiate among the following terminologies. i) global vs local allocation ii) equal vs proportional allocation 4. Explain different types of files. 5. Explain compaction 6. What is virtual memory? Explain 7. Suppose we have a demand paged memory. The page table is held in registers. it takes 8ms to service a page fault if an empty page is available or the replaced page is not modified, and 20ms if the replaced page is modified. memory access time is 100ns. Assume that the page to be replaced is modified 70% of the time. what is the maximum acceptable page fault rate for an effective access time of no more than 200ns? 8. What is demand paging? Explain 9. What is segmentation? Explain. what is demand segmentation? 10. What are the different access methods? Explain. 11. Explain the difference between Physical and logical address 12. Explain with neat diagram internal and external fragmentation. 13. Describe the action taken by the operating system when a page fault occurs. 14. Write short notes on swap space management. 15. What is dynamic storage allocation problem? Mention the names of different methods used to solve the above problem 16. Consider a logical address space of 8 pages of 1024 words each, mapped on to a physical memory of 32 frames. i) how many bits are there in the logical address? ii) How many bits are there in the physical address? 17. Explain in detail the implementation of paging 18. What is fragmentation? Explain its types and disadvantages 19. Write a note on file types and file structures 20. What is virtual memory and give its advantages 21. Explain the tem locality of reference and elaborate on its usefulness in presenting thrashing. 22. List the operations that can be performed on directory 23. What is page fault and how it is handled? 24. What is thrashing and explain its cause. 25. Define file and directory. Give one implementation of file directory. 26. Discuss the different file protection schemes. 27. Describe the SSTF disk scheduling algorithm using the following data. The dist head is initially at position-cylinder 53.the cylinder sequence of requests is 98, 183, 37, 122, 14, 124, 65. 67. find the total head movement. 28. Explain the locality model and the working set model 29. How deadlock can be prevented? Explain. PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem CS / IS 4 4 4* 5* 5 5* 5* 5 5* 5* 5 5* 5* 5* 5* 5* 6 6* 6* 6* 6* 6* 6 6 6 6* 6* 8 8* 10CS53 - 8 30. Describe the LRU page replacement algorithm, assuming there are 3 frames and the page reference string is 70120304230321201701 Find the number of page faults. 31. Write a note on “Internet use policy”. 32. Differentiate between External fragmentation and internal fragmentation 33. Explain with the help of supporting diagram how TLB improves the performance of a demand paging system. 34. Explain the disk structure 35. Explain the methods for free space management 36. Write a note on directory structure organization 37. Define file system. Explain the different directory structure. 38. What are the differences between internal fragmentation and external fragmentation? explain external fragmentation with an example 39. Explain the following disk scheduling algorithm with examples. iii) SSTF ii) SCAN iii)LOOK Comment on the selection of these scheduling methods. 40. Differentiate between the following a) Paging and Segmentation b) Page table and segment table 41. Explain any two page replacement algorithms 42. Explain the best fit, first fit and worst fit algorithm 43. Discuss the following page replacement algorithm with an example. i> Optimal ii> LRU 44. Differentiate between global and local replacement algorithms 45. 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 Find out the number of page faults if there are 4 page frames, using the following page replacement algorithm i) LRU ii) FIFO iii) Optimal 46. Suppose that a disk drive has 5000 cylinders, numbered 0 to 4999. the drive currently services a request at cylinder 143, and the previous request was at cylinder 125. the queue of pending request in FIFO order is 86,1470,913,1774,948,1509,1022,1750,130 Starting from the current position, what is the total distance(in cylinders) that the disk arm moves to satisfy all pending requests, for each of the following algorithms i)FCFS ii) SSFT iii) SCAN iv) LOOK v) C-SCAN. 47. Consider following sequence of memory reference from a 460-byte program 10,11,104,170,73,309,185,245,246,434,458,364 i) Give reference string assume page size of 100 bytes ii) Find Page fault rate assuming 200 bytes of Physical memory available using FIFO, LRU, Optimal replacement algorithms 48. Explain segmented memory management 49. What are the different disk scheduling algorithms explain 50. Give the differences between: i) Internal and external fragmentation ii) Paging and segmentation 51. Explain paging scheme of memory management. What hardware support is needed for its implementation? 52. Explain the linked allocation of disk space with a neat diagram. how does it compare with contiguous allocation 53. Discuss the various methods of allocation of disk space for file system 54. The queue of requests in FIFO is 86,147,91,177,94,150,102,175,130 What is the total head movement needed to satisfy the requests for the following PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 8* 8* 8* 8* 8 8 8 8* 8* 8* 10 10* 10* 10* 10 10* 10* 10 10* 10* 6* 10* 10* 10* 10 CS / IS 10CS53 - 9 Scheduling algorithms FCFS, SJF, SCAN, LOOK, C-SCAN 55. Differentiate between protection and security in file system. How they are implemented? 56. Explain different disk scheduling techniques with example. How are their performance measured? 57. Discuss the following page replacement algorithm with an example i) Optimal ii) LRU 58. Name the different file allocation methods. Explain the linked allocation of file implementation with merits and demerits. 59. What is disk scheduling? Explain FCFS and SCAN disk scheduling algorithms. 60. A virtual memory system has the following specification: Size of the virtual address space=64k Size of the physical address space=4k Page size=512 Virtual page# physical frame# 0 0 3 1 7 2 4 3 10 4 12 5 30 6 31 7 i) find all the virtual addresses that will generate a page fault compute the main memory addresses for the following virtual addresses. 24,3784,10250,30780 61. The available space list of a computer memory is specified as follows: Start address block address in words 100 50 200 150 450 600 1200 400 Determine the available space list after allocating the space for the stream of requests consisting of the following block sizes: 25,100,250,200,100,150 Use i) FIRST FIT ii) BEST FIT and iii) WORST FIT algorithms. Your answer should be in terms of the given available space list format only 62. Discuss the various ethical issues relating to information Technology. 63. What is paging? explain with an example 64. What is disk scheduling? Explain any three disk scheduling method with example. 65. Name the different file allocation and file access methods and clearly differentiate between them. Bring out the relative problems of contiguous allocation methods and explain how these problems are solved in linked allocation method. Bring out its relative demerits, if any 66. With respect to disk management, explain the following : i) Boot Block ii) Bad Block concepts. 67. Define 1.Thrashing 2.Beladys anomaly 3.Effective access time in demand paging 68. A process references 5 pages A, B , C, D, E in the following order A, B, C, D, A, E, B, C, E, D PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 10 10* 10* 10* 10* 10* 12* 12* 12* 12* 14* 8* 3* CS / IS 8 10CS53 - Assuming that the replacement algorithm is LRU and FIFO, find out the number of page faults during the sequence of references, starting with an empty main memory With 3 frames. 69. Suppose that the head of moving head disk with 200 tracks numbered 0 to 199 is currently serving the request at track 143 and has just finished a request at track 125. If the queue request is kept in FIFO order, 86, 147, 91, 177 , 94, 150, 102, 175, 130 What is the total head movement to satisfy these requests for i) FCFS II) SSTF disk scheduling algorithm. 70. Explain the linked allocation of disk space with a neat diagram. How does it compare with contiguous allocation. Describe the windows NT file system and mention its special features. 71. What do you mean by a address binding? Explain with the necessary steps, the binding of instructions and data to memory addresses. 72. What do you mean by a copy-on-write? Where is it used? Explain in brief. 73. What is dynamic storage allocation? Explain the commonly used strategies for dynamic storage allocation 74. Assume we have a paged memory system with associative registers (TLBs) to hold the most active page table entries. If the page table is normally held in memory and memory access time is 1 micro second, what would be the effective access time if 85% of all memory references find their entries in the associative registers. Assume that associative registers access time is zero. 75. Discuss the steps involved in handling page fault, with diagram. 76. Consider the following page reference string 7,0, 1,2,0,3,0,4,2,3,0,3,2, 1,2,0, 1, 7, 0, 1 . How many page faults would occur for FIFO page replacement algorithm, assuming three frames? 77. Given memory partitions of 100 K, 500 K, 200 K, 300 K and 600 K (in order) how would each of the first fit, best fit and worst fit algorithms work place processes of 212 K, 417 Km 112 K and 426 K (in order)? Which algorithm makes the most efficient use of memory? 8 10 5 4 12 4 6 4 4 UNIT 7: PROTECTION AND SECURITY Objective: The main objective of this chapter is to study how protection and security is provided by the operating system, what are the different mechanisms used and the different types of threats that a program as to face. 1. What are file protection methods? 2. What are the different access methods? Explain. 3. Explain the difference between protection and security 4. What are the problems encountered during protection? 5. What is access matrix? Explain its implementation 6. What are the goals of protection? 7. Discuss the different file protection schemes. 8. Write a note on “Internet use policy”. 9. What is a Hacker? What are the arguments for and against hacking? 10. Differentiate between protection and security in file system. How they are implemented? 11. Discuss the various ethical issues relating to information Technology. PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 11 4 5* 5 5 6 6 6* 8* 8* 10* 12* CS / IS 10CS53 - 12. Explain the terms ‘WORMS’ and ‘VIRUSES’ with reference to system threats 08* 13. Discuss the different methods used to solve the problem of security at the operating system level. 14. Briefly explain the various kinds of program threats and system threats. 10* 15. What is access matrix? Explain how the access matrix can be implemented effectively 10* 16. Explain different methods used to solve the problem of security at the operating system level 17. Explain the various questions that arise in revocation of access rights. 10* 10* 8 UNIT 8: CASE STUDY LINUX OPERATING SYSTEM Objective: The main objective of this chapter is to study History and development of Linux, Linux-process management and memory management, File systems, network structure and security. 1. What are components of Linux systems? 2. Explain Module management in Linux 3. What are 3 layers implemented in Linux kernel. 4. Explain the Windows NT-design principles 5. Explain the networking in Windows NT 6. Explain Windows-NT architecture 7. What are main features of UNIX? 8. Explain the process management in UNIX? 9. Explain security mechanism of Linux. 10. Write a short note on Design principle of Linux system. 11. What are the three main bodies of code in LINUX implementation? explain 12. Explain password mechanism in LINUX. 13. Explain Interprocess communication in Linux System 14. Explain Network structure, security in Linux system 15. Explain Design Principles of Linux System 16. Explain interface and memory management in Unix 17. Explain block, fragments, inode and mapping of a file descriptor to an inode in UNIXOS 18. What are the three classes of devices in LINUX? Explain the overall structure of the device-driver system in LINUX 19. Discuss the features of LINUX operating system. 5 5 5 5 5 5* 5* 5* 5 5* 5* 5* 6 6 8 8* 10* 10* 10* 20. Discuss the memory management with reference to Linux. 10* 21. Explain the three main components of a Linux system with a neat figure 10* 22. Distinguish between fork ( ) and clone ( ) system call. Also customize the clone ( ) system call to fork () functionality, with suitable modifications/settings. 23. Explain the Linux device drive the block structure 24. Explain Conflict resolution mechanism.of Unix 8 12 5 Note: ‘ * ‘ indicates questions appeared in previous exam papers. PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 12 CS / IS 10CS53 - Back to Home PESIT,B’LORE,SOUTH CAMPUS. – Education for the Real World – Course Information – BE. V-Sem 13 CS / IS 10CS53 -