File system is a certainthe order of the files on any storage medium in which these files are stored. As everyone knows, various types of files can be located on computers, mobile phones and other mobile devices. The organization of such storage determines the format of the information, the method of its storage and naming. All these parameters reflect the file structure of operating systems. Each specific file system determines its characteristics only:
- the size of the file or folder name;
- a set of system properties (attributes) for each type of file;
- The maximum possible size of the file partition.For some systems, it is also possible to perform some optional operations on files, the main such options are encryption and access control.
Any file structure of operating systems performs the following tasks:
- file naming;
- creates a unique interface for applications;
- determines the method of correlation and display of the logical model on the physical media;
- ensures the stability of the system;
- contains certain information that is necessary to ensure the interaction of the system with its other components (applications, services, kernel).
In addition, work with the file systemmulti-user type provides the ability to restrict and exclude another user from accessing data stored on a computer, as well as creates conditions for collaboration on files. The file structure of operating systems provides communication and interaction between the storage media and the API for accessing files. Functionally, it looks like this. At that moment, when any application accesses the file, the program does not know exactly where, on which particular disk, how the required information is located. The only thing that is known to the application is its own properties - the file size, its unique name and attributes. So, precisely because each file structure of operating systems is unique in its characteristics, the place and method of placing a specific file on the media (for example, on a hard disk) is established.
Сам жесткий диск представляет собой совокупность standard-sized clusters, their size, as a rule, is 512 bytes. These clusters are organized into files, and those, in turn, into directories. Due to a certain structure, files and directories are recognized as free and used, faulty. However, the file system is not directly related to the physical storage devices, there are so-called virtual systems, which are only a description of how to access files and directories.
Как и большинство структур, существующих в nature, the file has a hierarchical model of organization. This implies that all files on any OS are grouped into directories. The first operating system, where the hierarchical model of building such a structure was applied, was used in OS Multics, and then in UNIX. Directories are combined into trees, which can be several, as is done in the OS in DOS / Windows.
The most common in modern devices are file systems, which according to their functional purpose can be classified into:
- oriented to random access media (FAT32, HPFS, ext2);
- intended for sequential access media;
- for network and virtual systems;
- for optical devices and flash memory.
Each of them has a file system limitation peculiar only to it, this achieves the uniqueness and security of the OS, guaranteeing the unavailability of an outsider to the information.
