OperatingSystemConcepts-1-Introduction.pdf

Information Technology Institute Operating System Fundamentals © Copyright Information Technology Institute - 2016 Table of Content 1. Overview 1. Introduction 2. Computer System Structure 3....

Information Technology Institute Operating System Fundamentals © Copyright Information Technology Institute - 2016 Table of Content 1. Overview 1. Introduction 2. Computer System Structure 3. Operating System Structure 2. Process Management 1. Processes 2. CPU Scheduling 3. Deadlocks 3. Storage Management 1. Memory Management 2. Virtual Memory 3. File Management 4. Introduction to Cloud Computing © Copyright Information Technology Institute - 2016 2  Self Study Topics Virtual Memory Background. Demand Paging. Page Replacement. Allocation of frames. File-System Interface File Concept. Access Methods. Directory Structure. Protection. © Copyright Information Technology Institute - 2016 3  Self Study Topics (cont’d) File-System Implementation File System Structure. Allocation Methods. Free-Space Management. Directory Implementation. Recovery. © Copyright Information Technology Institute - 2016 4  Reference Computer Operating System Concepts Author: Silberschatz Publisher: Wiley ISBN: 0471250600 Handbook of Cloud Computing Author: Borko Furht, Armando Escalante Publisher: Springer ISBN: 978-1-4419-6523-3 © Copyright Information Technology Institute - 2016 5 Chapter One Introduction © Copyright Information Technology Institute - 2016 6  Table of Content Operating System Mainframe Systems Desktop Systems Multiprocessor Systems Distributed Systems Clustered System Real -Time Systems Handheld Systems Computing Environments © Copyright Information Technology Institute - 2016 7 OPERATING SYSTEM © Copyright Information Technology Institute - 2016 8  Operating System What is an Operating System? It acts as an intermediary between a user and his hardware Operating system objective Executes users programs Solves its problems Uses HW in an efficient manner Makes user life easier ;) © Copyright Information Technology Institute - 2016 9 Computer System Components © Copyright Information Technology Institute - 2016 10 1. Computer Hardware © Copyright Information Technology Institute - 2016 11  2. Operating System It controls and coordinates the use of the HW among the various application programs for the various users It manages and allocates resources It controls the execution of user programs and operations of I/O devices Kernel – the one program running at all times © Copyright Information Technology Institute - 2016 12  3. Application Programs Compilers Web browsers Spread sheets Word processors … © Copyright Information Technology Institute - 2016 13  4. Users People Machines Other Computers © Copyright Information Technology Institute - 2016 14 MAINFRAME SYSTEMS © Copyright Information Technology Institute - 2016 15  Mainframe Systems Reduce setup time by batching similar jobs Automatic job sequencing Automatically transfers control from one job to another. First rudimentary operating system © Copyright Information Technology Institute - 2016 16  Mainframe Systems Cont’d Memory Layout for a Simple Batch System © Copyright Information Technology Institute - 2016 17  Mainframe Systems Cont’d Multi-programmed Batch Systems Several jobs are kept in main memory at the same time, and the CPU is multiplexed among them © Copyright Information Technology Institute - 2016 18  Mainframe Systems Cont’d Time-Sharing Systems (Interactive Computing ) The CPU is multiplexed among several jobs that are kept in memory and on disk The CPU is allocated to a job only if the job is in memory A job swapped in and out of memory to the disk On-line communication between the user and the system is provided When the operating system finishes the execution of one command, it seeks the next “control statement” from the user’s keyboard On-line system must be available for users to access data and code © Copyright Information Technology Institute - 2016 19 DESKTOP SYSTEMS © Copyright Information Technology Institute - 2016 20  Desktop Systems Personal computers Computer system dedicated to a single user I/O devices Keyboards Mice Display screens Small printers User convenience and responsiveness Can adopt technology developed for larger operating system Often individuals have sole use of computer and do not need advanced CPU utilization of protection features May run several different types of operating systems (Windows, MacOS, UNIX, Linux)© Copyright Information Technology Institute - 2016 21 MULTIPROCESSOR SYSTEMS © Copyright Information Technology Institute - 2016 22  Parallel Systems Systems with more than one CPU in close communication Also known as multiprocessor systems Tightly coupled system processors share memory and a clock; communication usually takes place through the shared memory Advantages of parallel system: Increased throughput Economical Increased reliability graceful degradation fail-soft systems © Copyright Information Technology Institute - 2016 23 DISTRIBUTED SYSTEMS © Copyright Information Technology Institute - 2016 24  Distributed Systems Distribute the computation among several physical processors Loosely coupled system Each processor has its own local memory processors communicate with one another through various communications lines, such as high-speed buses or telephone lines Advantages of distributed systems Resources Sharing Computation speed up load sharing Reliability © Copyright Information Technology Institute - 2016 25  Distributed Systems Cont’d Requires networking infrastructure Local area networks (LAN) or Wide area networks (WAN) May be either client-server or peer-to-peer systems © Copyright Information Technology Institute - 2016 26 CLUSTERED SYSTEMS © Copyright Information Technology Institute - 2016 27  Clustered Systems Clustering allows two or more systems to share storage Provides high reliability Asymmetric clustering: one server runs the application or applications while other servers standby Symmetric clustering: all N hosts are running the application or applications © Copyright Information Technology Institute - 2016 28 REAL-TIME SYSTEMS © Copyright Information Technology Institute - 2016 29  Real-Time Systems Often used as a control device in a dedicated application such as controlling scientific experiments, medical imaging systems, industrial control systems, and some display systems Well-defined fixed-time constraints Real-Time systems may be either hard or soft real-time © Copyright Information Technology Institute - 2016 30  Real-Time Systems Cont’d Hard real-time: Secondary storage limited or absent, data stored in short term memory, or read-only memory (ROM) Conflicts with time-sharing systems, not supported by general-purpose operating systems Soft real-time Limited utility in industrial control of robotics Integrate-able with time-share systems Useful in applications (multimedia, virtual reality) requiring tight response times © Copyright Information Technology Institute - 2016 31 HANDHELD SYSTEMS © Copyright Information Technology Institute - 2016 32  Handheld Systems Personal Digital Assistants (PDAs) Cellular Phone & Smart Phone Issues: Limited memory Slow processors Small display screens © Copyright Information Technology Institute - 2016 33  Computing Environments Traditional computing PCs, Servers, limited remote access Web-Based Computing Client-server and web services, convenient remote access, location-less servers Embedded Computing Very limited operating system features Little or no user interface, remote access © Copyright Information Technology Institute - 2016 34 © Copyright Information Technology Institute - 2016 35