Operating System- 2 marks
1. What is meant by Mainframe Systems?
Mainframe systems are the first computers developed to tackle many commercial and scientific applications. These systems are developed from the batch systems and then multiprogramming system and finally time sharing systems.
2. What is meant by Batch Systems?
In this, operators batched together jobs with similar needs and ran through the computer as a group .The operators would sort programs into batches with similar requirements and as system become available, it would run each batch.
3. What is meant by Multiprogramming?
Several users simultaneously compete for system resources (i.e) the job currently waiting for I/O will yield the CPU to another job which is ready to do calculations, if another job is waiting. Thus it increases CPU utilization and system throughput.
4. What is meant by Time-sharing Systems? Time Sharing is a logical extension of multiprogramming .Here, CPU executes multiple jobs by switching among them, but the switches occur so frequently that the users can interact with each program while it is running.
5. What are the Components of a Computer System?
1. Application Programs 2. System Program 3. Operating System 4. Computer Hardware
6. What are the advantages of Multiprogramming? Increased System Throughput Increased CPU utilization
7. What is Multiprocessor System? Multiprocessor systems have systems more than one processor for communication, sharing the computer bus, the memory, clock & peripheral devices.
8. What are the advantages of multiprocessors?
Increased throughput Economy of scale Increased reliability
9. What is meant by clustered system? Clustered systems are collection of multiple CPUs to accomplish computational work. Those systems share storage and are closely linked via LAN networking.
10. What are the types of clustering?
Symmetric Clustering Asymmetric Clustering & Clustering over a WAN
11. What is meant by Asymmetric Clustering?
In this clustering, one machine is in hot standby mode, while the other is running the application. The hot standby machine just monitors the active server. If that server fails, hot stand by host become the active server.
12. What is meant by Symmetric clustering?
In this, two or more hosts are running applications and they are monitoring each other. This clustering requires more than one application be available to run and it uses all of the available hardware.
13. What is meant by parallel clusters?
Parallel clusters allow multiple hosts to access the same data on the shared storage. Each machine has full access to all data in the database.
14. What is meant by symmetric multiprocessing?
In Symmetric multiprocessing, each processor runs an identical copy of the operating system and these copies communicate with one another as needed.
15. What is meant by Asymmetric Multiprocessing?
In Asymmetric multiprocessing, each processor assigned a specific task. A master processor controls the system and the other processors either look to the master for instruction or have predefined tasks. This master processor also schedules and allocates work to the slaves.
16. What is meant by Real time system?
Real time systems are systems that have their in-built characteristics as supplying immediate response. In real time system, each process is assigned a certain level of priority according to the relative importance of the events to be processed.
17. What are the advantages of distributed systems?
Resource sharing Load balancing Reliability Communication link easy
18. What are the applications of real-time systems?
controlling the machines
Instruments
Industrial process
Landing & tasking off aero planes
19. What are the types of Real time systems?
Hard Real Time System Soft Real Time System
20. What is meant by Hard Real time systems?
They are generally required to and they guarantee that the critical tasks are completed in given amount of time.
21. What is meant by soft real time system?
It provides priority to the tasks based on their criticality. It does not guarantee completion of critical tasks in time.
22. What is meant by distributed systems?
A distributed system is basically a collection of autonomous computer systems which co-operate with one another through their h/w and s/w interconnections.
23. What are the disadvantages of distributed systems?
Security weakness Over dependence on performance and reliability Maintenance and control become complex
24. What are the modes of operation in Hardware Protection?
Monitor Mode User Mode
25. What are Operating Services?
Normally, an operating system provides certain services to programs and to the users of those programs. Some of them are: I/O operations Program Execution. Communications File-system manipulation Error Detection
26. What is System Programs?
System programs provide a convenient environment for program development and execution. Some of these programs are user interfaces to system calls and others are more complex. Some of them are: Status Information File Management Programming Language support File modification Program loading, execution and communication.
27. What is meant by System Calls?
The System Calls acts as a interface to a running program and the Operating system. These system calls available in assembly language instructions.
28. What is Virtual machine?
The Application programs view everything under them in the hierarchy as though the system programs were part of the machine itself. This layered approach is taken as the logical conclusion in the concept of a Virtual machine.
29. What is meant by Hand held Systems?
Handheld Systems have a small amount of memory including slow processors and also small display screens and are of limited size and they always have connectivity to a network.
30. What is known as system utilities?
Most operating systems are supplied with programs that solve common problems or perform common operations. Such programs include web browsers, word processors and text formatters, spread sheets, database systems, compilers, plotting and games. These programs are known as system utilities