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CS240 Sequence 2
OS objectives, OS services, Kernel, Linux
Question | Answer |
---|---|
What is an Operating System? | >A program that controls the execution of application programs >An interface between applications and hardware |
What are the Operating Systems objectives? | >Convenience >Efficiency >Ability to evolve |
What is Convenience? | Makes the computer more convenient to use |
What is Efficiency ? | Allows computer system resources to be used in an efficient manner |
What is Ability to Evolve? | Permit effective development, testing, and introduction of new system functions without interfering with service |
Whats the Layers of Computer System in order (top to bottom)? | 1. Application Programs 2. Utilities 3. Operating System 4. Computer Hardware |
What is the layer of computer systems that end users use? | Application Programs |
What is the layer of computer systems that programmers use? | >Utilities >Operating System |
What is the layer of computer systems that operating system designers use? | computer hardware |
What are the services provided by the operating system? | >Program development >Program execution >Access to I/O devices >Controlled access to files >Memory management >System access >Network support >Error detection and response >Accounting |
what are examples of program development services? | Editors debuggers |
What happens during error detection and response ? | Operating system cannot grant request of application |
what are the types of errors? | >Internal and external hardware errors >Software errors |
What are causes of Internal and External hardware errors? | >Memory error >Device failure |
What are causes of Software errors? | >Arithmetic overflow >Access forbidden memory locations |
What is accounting ? | >Collect usage statistics >Monitor performance >Used to anticipate future enhancements >Used for billing purposes >check out the log files of a unix system |
What is the Operating System informal definition | >An OS is just a program that is executed |
what is an operating system responsible for? | managing resources |
What is a kernel? | >Portion of operating system that is in main memory >Contains most frequently used functions |
What is another name of a kernel? | the nucleus |
Why does an OS need to evolve? | >Hardware upgrades >new types of hardware >New services >Fixes |