Presentation on theme: "BARNALI CHAKRABARTY. What is an Operating System ?"— Presentation transcript:
What is an Operating System ?
Features of Operating System Multi user Multiprocessing Multitasking Multithreading Real time
Classification of Services [Chow07] Primitive Services –fundamental functions that the kernel must provide Services by System Servers- services that need not reside in the kernel but are still essential Value Added Servers –services that are not essential in implementation but are useful in supporting distributed applications
Primitive Services Communication- Exchange of Information between processes Synchronization- Coordination of Events
Services by System Servers Name Server - used to locate users, processes or machines Network Server –used to translate addresses and locations obtained from Name server Time Server-synchronization of processes to maintain a total order of event occurrences File Server- managing shared file system resources
Value Added Services Web Server – accepts requests from the clients, processes it and returns a response Group Server –manages creation and termination of groups of interacting processes
Classification of Services [Galvin05] Services that are helpful to users Services for efficient operation of system
Operating System Services that are helpful to users User Interface Program Execution I/O Operations File System Operations Error Detection
User Interface The means by which the user interacts with the system Consists of Input Output
Program Execution Loading Running Execution
I/O Operations The communications between the computer and the outside world
File System Manipulation Programs need to read and write files and directories, create and delete them, search them, list file Information
Error Detection OS needs to constantly monitor possible errors and should take an appropriate action to rectify the error
Services for efficient operation of system Resource Allocation Accounting Protection and Security
Resource Allocation Resource allocation must be properly done when multiple users or multiple jobs running concurrently.
Accounting OS keeps track of what kind of resources used, how many users etc
Protection and Security Ensuring that all access to system resources is controlled Access to the system from outsiders requires user authentication
WebOS: A Framework of OS services for wide area Applications[A.Vahdat97] Global Naming Wide-Area File System Security and Authentication Process Control
Privacy as an Operating System Service [S.Iosannidis06] Approach 1.Transparent, privacy-providing storage and network 2. Privacy-enhanced system calls 3. Privacy Libraries 4. Privacy-policy Management
System Support for Many Task Computing [E.V.Hensbergen,08] The paper deals with issues of scale by leveraging the large number of nodes to spread operating systems services and components across the machine, tightly coupling the operating system. The authors plan on provisioning nodes to provide workload execution, aggregation, and system services, and dynamically re-provisioning nodes as necessary to accommodate changes, failure, and redundancy.
Future Work Implementation and Development of Liquid Operating system, which is spontaneous and adaptive to dynamically meet the changing requirements of the user.
References http://www.webopedia.com/TERM/o/operating_system.html Wikipedia Distributed Operating Systems and Algorithm Analysis, Andy Chow & Theodore Johnson,1997  Operating System Concepts, Silberschatz, Galvin and Gagne,2005  WebOS: Operating System Services for Wide Area Applications,Amin Vahdat et al,1997  Privacy as an operating system service,Ioannidis,S; Sidiroglou,S; D. Keromytis,A;Proceedings of the 1st USENIX Workshop on Hot Topics in Security,2006  System support for many task computing, Van Hensberger, E.; Minnich, R.;Many-Task Computing on Grids and Supercomputers, MTAGS Workshop on Nov Page(s):1 - 8