CS197OSTYPES.pdf
- 1. OPERATING SYSTEM TYPES OF OPERATING SYSTEM 1. Batch Operating System 2. Multiprogramming operating system 3. Time-Sharing Operating Systems 4. Distributed Operating System 5. Network Operating System
- 2. 1. Batch Operating System This type of operatingsystem does not interact with the computerdirectly. There is an operatorwhich takes similar jobs having the same requirement and group them into batches. It is the responsibility of the operatorto sort jobs with similar needs. Advantages of Batch Operating System: It is very difficult to guess or know the time required for any job to complete. Processors of the batch systems know how long the job would be when it is in queue Multipleusers can share the batch systems The idle time for the batch system is very less It is easy to manage large work repeatedlyin batch systems.
- 3. Disadvantages of Batch Operating System: The computer operators should be well known with batch systems Batch systems are hard to debug It is sometimes costly The other jobs will have to wait for an unknown time if any job fails Examples of Batch based Operating System: Payroll System, Bank Statements, etc.
- 4. 2.MULTIPROGRAMMING OPERATING SYSTEM when two or more programs reside in memory at the same time, is referred as multiprogramming. Multiprogramming assumes a single shared processor. Multiprogramming increases CPU utilization by organizing jobs so that the CPU always has one to execute. An OS does the following activities related to multiprogramming. The operatingsystem keeps several jobs in memory at a time. This set of jobs is a subset of the jobs kept in the job pool. The operatingsystem picks and begins to execute one of the jobs in the memory. Multiprogramming operating systems monitor the state of all active programs and system resources using memory management programs to ensures that the CPU is never idle, unless there are no jobs to process.
- 5. Advantages High and efficient CPU utilization. User feels that many programs are allotted CPU almost simultaneously. Disadvantages CPU scheduling is required. To accommodate many jobs in memory, memory management is required.
- 6. user gets the time of CPU as they use a single system. These systems are also known as Multitasking Systems. The task can be from a single user or different users also Each task is given some time to execute so that all the tasks work smoothly. Each. The time that each task gets to execute is called quantum. After this time interval is over OS switches over to the next task. Advantages of Time-SharingOS: Each task gets an equal opportunity Fewer chances of duplication of software CPU idle time can be reduced 3. Time-Sharing Operating Systems
- 7. Disadvantagesof Time-SharingOS: Reliability problem One must have to take care of the security and integrity of user programs and data Data communication problem Examples of Time-SharingOSs are: Multics, Unix, etc.
- 8. 4. Distributed Operating System These types of the operatingsystem is a recent advancement in the world of computertechnology and are being widely accepted all over the world and, that too, with a great pace. Various autonomousinterconnectedcomputers communicate with each other using a shared communication network. Independent systems possess their own memory unit and CPU. These are referred to as looselycoupledsystems or distributedsystems. These system’s processors differ in size and function. The major benefit of working with these types of the operatingsystem is that it is always possible that one user can access the files or software which are not actuallypresent on his system but some other system connectedwithin this network i.e., remote access is enabledwithin the devices connectedin that network.
- 9. Advantages of Distributed Operating System: Failure of one will not affect the other network communication, as all systems are independent from each other Electronic mail increases the data exchange speed Since resources are being shared, computation is highly fast and durable Load on host computer reduces These systems are easily scalable as many systems can be easily added to the network Delay in data processing reduces Disadvantages of Distributed Operating System: Failure of the main network will stop the entire communication To establish distributed systems the language which is used are not well defined yet These types of systems are not readily available as they are very expensive. Not only that the underlying software is highly complex and not understood well yet Examples of Distributed Operating System are- LOCUS, etc.
- 10. 5. Network Operating System These systems run on a server and provide the capability to manage data, users, groups, security, applications, and othernetworking functions. These types of operatingsystems allow shared access of files, printers, security, applications, and othernetworking functions over a small private network. One more important aspect of Network Operating Systems is that all the users are well aware of the underlyingconfiguration, of all otherusers within the network, their individual connections, etc. and that’swhy these computers are popularlyknown as tightly coupledsystems. Advantages of Network OperatingSystem: Highly stablecentralized servers Security concerns are handledthrough servers New technologies and hardware up-gradation are easily integrated into the system Server access is possible remotely from different locations and types of systems
- 11. Disadvantagesof Network OperatingSystem: Servers are costly User has to depend on a central location for most operations Maintenanceand updatesare required regularly Examples of Network Operating System are: Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell NetWare, and BSD, etc.
- 12. 6. Real-Time Operating System These types of OSs serve real-time systems. The time interval required to process and respond to inputs is very small. This time interval is called responsetime. Real-timesystems are used when there are time requirements that are very strict like missile systems, air traffic control systems, robots, etc.
- 13. Two types of Real-Time Operating System which are as follows: Hard Real-Time Systems: These OSs are meant for applications where time constraints are very strict and even the shortest possible delay is not acceptable. These systems are built for saving life like automatic parachutes or airbags which are required to be readily available in case of any accident. Virtual memory is rarely found in these systems. Soft Real-Time Systems: These OSs are for applications where for time-constraint is less strict.
- 14. Advantages of RTOS: Maximum Consumption: Maximum utilization of devices and system, thus more outputfrom all the resources Task Shifting: The time assigned for shifting tasks in these systems are very less. For example, in oldersystems, it takes about 10 microseconds in shifting one task to another,and in the latest systems, it takes 3 microseconds. Focus on Application: Focus on running applicationsand less importance to applicationswhich are in the queue. Real-time operating system in the embedded system: Since the size of programs are small, RTOS can also be used in embedded systems like in transportand others. ErrorFree: These types of systems are error-free. Memory Allocation: Memory allocationis best managed in these types of systems.
- 15. Disadvantagesof RTOS: Limited Tasks:Very few tasks run at the same time and their concentration is very less on few applicationsto avoid errors. Use heavy system resources:Sometimes the system resources are not so good and they are expensive as well. ComplexAlgorithms:The algorithms are very complex and difficult for the designer to write on. Device driver and interrupt signals:It needs specific device drivers and interruptssignals to respond earliest to interrupts. Thread Priority:It is not good to set thread priority as these systems are very less prone to switching tasks. Examples of Real-TimeOperatingSystems are: Scientific experiments, medical imaging systems, industrial controlsystems, weapon systems, robots, air traffic controlsystems, etc.