All the systems do not have the same design structure, Many Operating System share the same goal for supporting the following types of system components.
Process Management:
An OS Manages many kinds of activities ranging from the user programs to system programs like printer spooler, name servers, file servers etc. each of these activities is encapsulated in a process. A process includes the complete execution context (code, data, PC, registers, OS resources in use, etc.)
The OS is responsible for the following.
- creation and deletion of user and systems possess;
- suspension and resumption of processes;
- a mechanism for process synchronization;
- A mechanisms for process communication; and
- A mechanism for deadlock handling.
Memory Management
The primary memory is a large array of words or byte which has its own address. Any process that wants its execution, must reside in the main memory. The main memory is directly accessed by the Central Processing Unit (CPU) of the computer system.
The main activities of the memory Management are:
- Keeps track of which part of memory is currently being used and by whom;
- Decides which process is loaded into memory and
- Allocates and de-allocates memory space as needed.
File Management
A file is a collection of related information that is defined by its creator. The computer can store files on the disk (secondary storage), which provides long term storage. Some examples of storage media are magnetic tape, magnetic disk, optical disk, etc each of these media has its own properties like speed, capacity, data transfer rate and access methods. A file system is organized into directories, which contain file and other directories.
The major activities of File management system are:- The Creation and deletion of files;
- Creation and deletion of directories
- The support of primitives for manipulation files and directories;
- Mapping of files onto secondary storage; and
- The backup of files on stable storage media.
I/O System Management
The I/O system hides the details of hardware devices from the user. It's only the device driver that knows the details of the specific device to whom it is assigned.
Secondary- Storage Device Management
A computer System has several levels of storage includes primary storage, secondary storage and cache storage. The instructions and data must be placed in primary storage or cache to be referenced by a running program. Since, the main memo rm is too small to accommodate all programs and data, and its data is lost when power is lost, so the computer system must provide a secondary level of storage that is also called backup storage which provides backup to the main memory.
Secondary storage consists of tapes, disks, and other media designed to hold information that will eventually be accessed in the primary storage. The memory, secondary memory and cache memory are ordinarily divided into bytes. Each location in the storage device has an address. The set of address that are available to a program is called an address space.
The three major activities of an operating system in regard to secondary storage management are:- Managing the free space available on the secondary storage device;
- Allocation of storage space when new files have to be written; and
- Scheduling the requests for memory access.
Networking
A distributing system is a collection of processors that do not share memory, peripheral devices or a clock. Instead , each processor has its own local memory and clock. The processors Communicate with each other through a communication line called network. The network may be fully or partially connected .
the communication network design must consider a message passing scheme and the various connection strategies and the programs of contention and security.
A distributed system collects physically separate. Possibly Heterogeneous systems into a coherent system, providing the user with access to be various resources that the system maintains. The access to a shared resources allows computations speed up, increased functionality, increased data availability, and enhanced reliability.
The operating systems generalize network access as a form file access, with the details generalize access as a form file access, with the details of networking being contained in the device drives of various network interfaces.