INTRODUCTION II Flashcards
Define the following:
Resource Allocator
Control Program
Kernel
Resource allocator- Manages and allocates resources.
Control program- Controls the execution of user programs and operations of I/O devices
Kernel- It is a computer program at the core of a computer’s operating system with complete control over everything in the system. Always resident in memory.
Define the following:
Resource Allocator
Control Program
Kernel
Resource allocator- Manages and allocates resources.
Control program- Controls the execution of user programs and operations of I/O devices
Kernel- It is a computer program at the core of a computer’s operating system with complete control over everything in the system. Always resident in memory.
What are the two main components of an operating system
Kernel
Is an active part of an OS i.e., it is the part of OS running at all times. It is a program which can interact with the hardware. Ex: Device driver, dll files, system files etc.
Shell
Is called as the command interpreter. It is a set of programs used to interact with the application programs.
It is responsible for execution of instructions given to OS (called commands).
Describe the two viewpoints from which an operating system can be explored from
User View:
From the user’s point view, the OS is designed for
one user to monopolize its resources, to maximize
the work that the user is performing and for ease of
use.
System View:
From the computer’s point of view, an operating
system is a control program that manages the
execution of user programs to prevent errors and
improper use of the computer. It is concerned with
the operation and control of I/O devices.
What are the functions of operating systems
Process Management
Memory Management
File Management
I/O System Management
Networking (In distributed systems)
Describe the process management function of the operating system
The operating system is responsible for the following
activities in connection with process management.
-Process creation and deletion.
-Process suspension and resumption.
-Provision of mechanisms for:
* process synchronization
* process communication
Describe the memory management function of the operating system
The operating system is responsible for the following activities in connections with memory management:
-Keep track of which parts of memory are currently being used and by whom.
-Decide which processes to load when memory space becomes available.
-Allocate and de-allocate memory space as needed.
Describe the file management function of the operating system
The operating system is responsible for the following activities in connections with file management:
-File creation and deletion.
-Directory creation and deletion.
-Support of primitives for manipulating files and directories.
-Mapping files onto secondary storage.
-File backup on stable (nonvolatile) storage media.
Describe the I/O management function of the operating system
q The I/O system consists of:
ü A buffer-caching system
ü A general device-driver interface
ü Drivers for specific hardware devices
Describe the Secondary Storage/Memory Management function of the operating system
The operating system is responsible for the following activities in connection with disk management:
-Free space management
-Storage allocation
-Disk scheduling
Describe the Networking function of the operating system
A distributed system provides user access to various system resources.
Access to a shared resource allows:
-Computation speed-up
-Increased data availability
-Enhanced reliability
List some of the operating system services which are for the benefit of the user
Program Execution
The operating system provides an environment where the user can conveniently run programs.
Running a program involves the allocating and deallocating memory, CPU scheduling in case of multiprocessing.
I/O Operations
Operating systems provide I/O makes it convenient for the users to run programs.
File System Manipulation
The output of a program may need to be written into new files or input taken from some files. The operating system provides this service.
Communications
The processes need to communicate with each other to exchange information during execution. It may be
between processes running on the same computer or running on the different computers.
Error Detection
The operating system constantly monitors the
system for detecting the errors. This relieves the user of the worry of errors propagating to various part of the system and causing malfunctioning.
What are the two ways communications can occur
Shared memory
Message passing
List some of the operating system services which are for the benefit of the system
Resource allocation
When multiple users are logged on the system
or multiple jobs are running at the same time,
resources must be allocated to each of them.
Many different types of resources are managed
by the operating system.
Accounting
The operating systems keep track of which users
use how many and which kinds of computer
resources. This record keeping may be used for
accounting (so that users can be billed) or
simply for accumulating usage statistics.
Protection
Protection involves ensuring that all access to system resources is controlled.
Security of the system from outsiders is also important. Such security starts with proper authentication
