The file system is ... File systems: what is FAT and NTFS. Android file system

Files on the computer are created and placed on the basis of system principles. Thanks to their implementation, the user is able to comfortably access the right information without worrying about the complex algorithms for accessing it. How is the work of file systems organized? Which ones are the most popular today? What are the differences between file systems adapted for a PC? And those that are used in mobile devices - smartphones or tablets?

File Systems: Definition

According to the common definition, a file system is a set of algorithms and standards that are used to organize the effective access of a PC user to data located on a computer. Some experts consider it to be part of the operating system. Other IT experts, recognizing the fact that it is directly connected with the OS, believe that the file system is an independent component of managing computer data.

How were computers used before the file system was invented? Informatics - as a scientific discipline - recorded the fact that for a long time data management was carried out through structuring within the algorithms laid down in specific programs. Thus, one of the criteria of the file system is the availability of standards that are the same for most programs that use data access.

How file systems work

The file system is, first of all, a mechanism that involves the use of computer hardware resources. As a rule, we are talking about magnetic or laser media - hard disks, CDs, DVDs, flash drives, diskettes that have not yet expired. In order to understand how the corresponding system works, let's define what is the actual file itself.

According to the common definition among IT experts, this is a fixed-value data area expressed in basic information units-bytes. A file is located on the disk medium, usually in the form of several interconnected blocks that have a specific "address" of access. The file system determines these very coordinates and "reports" them, in turn, the OS. Which intelligently translates the relevant data to the user. There is an access to the data in order to read them, modify them, create new ones. The specific algorithm for working with "coordinates" of files can be different. It depends on the type of computer, OS, the specifics of the stored data and other conditions. Therefore, there are different types of file systems. Each of them is optimized for use in a particular OS or for working with certain types of data.

Adaptation of disk medium to use by algorithms of a particular file system is called formatting. The corresponding hardware elements of the disk - clusters - are prepared for the subsequent recording of files on them, as well as reading them in accordance with the standards laid down in this or that data management system. How can I change the file system? In most cases, this can only be done by reformatting the storage medium. As a rule, the files are deleted. However, there is an option where you can still use special programs, although this usually requires a lot of time, change the data management system, leaving the latter untouched.

File systems do not work without errors. Some failures in the organization of work with data blocks are possible. But they are in most cases not critical. As a rule, there are no problems with how to fix the file system, fix errors. In Windows, for this, in particular, there are built-in software solutions available for any user. Such as, for example, the program "Disk Check".

Varieties

What types of file systems can be called the most common? Probably, first of all those that are used by the most popular OS for PCs in the world are Windows. The main Windows file systems are FAT, FAT32, NTFS and their various modifications. Along with computers, smartphones and tablets have gained popularity. Most of them, if we talk about the global market and do not consider the differences in technological platforms, is controlled by Android and iOS. These operating systems use their own algorithms for working with data, different from those that characterize Windows file systems.

Standards open to all

Note that recently in the world electronics market there is some unification of the standards in the aspect of operating the OS with different types of data. This can be traced in two aspects. First, on different devices running two dissimilar OS types, the same file system is used, which is equally compatible with each OS. Secondly, modern versions of the OS, as a rule, are able to recognize not only typical for themselves file systems, but also those that are traditionally used in other OSes - both through built-in algorithms and with the help of third-party software. For example, modern versions of Linux, as a rule, easily recognize the marked file systems for Windows.

Structure of the file system

Despite the fact that the types of file systems are presented in a large enough number, they work in general on very similar principles (the general scheme we outlined above) and within the framework of similar structural elements or objects. Consider them. What are the main objects of the file system?

One of the key is the catalog. It is an isolated data area in which files can be placed. The directory structure is hierarchical. What does it mean? One or more directories can be placed in another. Which, in turn, is part of the "superior". The most "main" is the root directory. If we talk about the principles on the basis of which the Windows file system works - 7, 8, XP or another version, - the root directory is a logical disk, denoted by the letter - usually C, D, E (but you can configure any that is in English alphabet). As for, for example, Linux OS, then the root directory is the magnetic medium as a whole. In this operating system and other OS, based on its principles - to that is Android - logical disks are not used. Can I store files without directories? Yes. But this is not very convenient. In fact, comfort in using the PC is one of the reasons for the introduction of the principle of data distribution in catalogs in file systems. By the way, they can be called differently. In Windows, directories are called folders, in Linux - basically the same. But the traditional, used for many years, the name of the directories in this OS is "directories". As in the previous Windows and Linux OS - DOS, Unix.

In the environment of IT-specialists there is no unambiguous opinion as to whether to consider the file as a structural element of the corresponding system. Those who believe that this is not entirely correct argue their point of view by the fact that the system may well exist without files. Let it from a practical point of view and useless phenomenon. Even if no files are recorded on the disk, the corresponding system can still be present. As a rule, magnetic media sold in stores do not contain any files. But they already have a corresponding system. According to another point of view, files should be considered an integral part of the systems with which they are managed. Why? And because, according to experts, the algorithms for their use are adapted primarily to work with files within certain standards. The systems are not designed for anything else.

Another element that is present in most file systems is a shortcut. It is a data area containing information about the location of a particular file in a specific location. That is, you can place a shortcut in one place of the disk, but you can provide access to the data area that is located in another part of the media. To consider that shortcuts are full objects of the file system, you can, if you agree that such are also files.

One way or another it will not be a mistake to say that all three types of data - files, shortcuts and directories - are elements of the corresponding systems. At least, this thesis will correspond to one of the common points of view. The most important aspect that characterizes how the file system works is the principles of naming files and directories.

Names of files and directories in different systems

If we agree that the files are all the same elements of the corresponding systems, then we should consider their basic structure. What can be noted in the first place? For the convenience of access to them in most modern data management systems, a two-level file naming structure is provided. The first level is the name. The second is expansion. Take for example the music file Dance.mp3. Dance is the name. Mp3 - extension. The first is to disclose to the user the essence of the contents of the file (and for the program to be a reference point for quick access). The second denotes the file type. If it's Mp3, then it's easy to guess that it's about music. Files with the Doc extension are usually documents, Jpg - pictures, Html - web pages.

Catalogs, in turn, have a single-level structure. They have only a title, no expansion. If we talk about the differences between different types of data management systems, the first thing that should be paid attention is how the principles of naming files and directories are implemented in them. Regarding Windows, the specifics are as follows. In the world's most popular operating system, files can be named in any language. The maximum length, however, is thus limited. Its specific interval depends on the data management system used. Usually this is between 200 and 260 characters.

A general rule for all operating systems and their corresponding data management systems is that files with the same name can not be in the same directory. In Linux, there is some kind of "liberalization" of this rule. In one directory there can be files with the same letters, but in different registers. For example, Dance.mp3 and DANCE.mp3. In Windows, this is impossible. The same rules are also established in the aspect of placing directories inside others.

Addressing files and directories

Addressing files and directories is the most important element of the corresponding system. In Windows, its custom format might look like this: C: / Documents / Music / is access to the Music directory. If we are interested in a particular file, the address might look like this: C: /Documents/Music/Dance.mp3. Why "custom"? The fact is that at the level of software-hardware interaction of computer components the structure of access to files is much more complicated. The file system determines the location of the file blocks and interacts with the OS for the most part within the operations hidden from the user. However, it is extremely rare for a PC user to use other "address" formats. Almost always access to the files is carried out in the specified standard.

Comparison of file systems for Windows

We studied the general principles of the operation of file systems. Let's consider now features of the most widespread their kinds. In Windows, the most common file systems are FAT, FAT32, NTFS, and exFAT. The first in this series is considered obsolete. It, however, for a long time was a certain leader of the industry, but as the technology of the PC grew its capabilities ceased to meet the needs of users and the resource requirements of the software.

Called to replace the FAT file system is FAT32. According to many IT experts, now it is the most popular, if we talk about the PC market running Windows. It is most often used when storing files on hard disks and flash drives. It can also be noted that this data management system is regularly used in memory modules of various digital devices - telephones, cameras. The main advantage of FAT32, which is allocated by IT experts, so it's versatility. Despite the fact that this file system was created by Microsoft, most of the modern OS, including those that are installed on these types of digital equipment, can work with data within the framework of the algorithms embedded in it.

There are a number of shortcomings in the FAT32 system. First of all, you can note the limitation on the size of one file taken - it can not be more than 4 GB. Also, in the FAT32 system, you can not use the built-in Windows tools to specify a logical disk, the size of which would be larger than 32 GB. But this can be done by installing additional specialized software.

Another popular file management system that Microsoft developed is NTFS. According to some IT experts, it surpasses FAT32 in most parameters. But this thesis is true, if we are talking about the operation of a computer running Windows. The NTFS system is not as versatile as FAT32. Features of its operation make the use of this file system not always comfortable, in particular, in mobile devices. One of the key advantages of NFTS is its reliability. For example, in cases where the hard disk suddenly turns off the power, the likelihood that the files will be damaged is minimized, thanks to the duplication of data access provided in NTFS.

One of the newest file systems from Microsoft is exFAT. It is best adapted for flash drives. The basic principles of working in it are the same as in FAT32, but there is also a significant upgrade in some aspects: for example, there are no restrictions on the size of a single file. At the same time, the exFAT system, as many IT experts note, is among those that have low universality. On computers running OSes other than Windows, working with files when using exFAT can be difficult. Moreover, even in some versions of Windows itself, such as XP, data on disks formatted using exFAT algorithms may not be readable. You will need to install an additional driver.

Note that due to the use of a fairly wide range of file systems in Windows, the user may experience periodic difficulties in the aspect of compatibility of various devices with the computer. In some cases, for example, you need to install the WPD file system driver (Windows Portable Devices). Sometimes it may not be at hand for the user, so that the external storage medium can not recognize the OS. The WPD file system may require additional software tools to adapt to the operating environment on a particular computer. In some cases, the user will be forced to contact IT specialists to solve the problem.

How to determine which file system - exFAT or NTFS, and maybe FAT32 - is optimal for use in specific cases? Recommendations of IT-specialists in general are as follows. Two main approaches can be used. According to the first, you should distinguish between typical file systems of hard disks, as well as those that are better adapted to flash drives. FAT and FAT32, according to many experts, are better suited for "flash drives", NTFS - for hard drives (due to technological features of working with data).

In the second approach, the value of the carrier is important. If you are talking about using a relatively small amount of disk or flash drive, you can format them in the FAT32 system. If the disk is larger, then you can try exFAT. But only if you do not intend to use media on other computers, especially those that do not have the latest versions of Windows. If it is a question of large hard disks, including external ones, then it is advisable to format them in NTFS. Approximately these are the criteria by which the optimal file system can be chosen - exFAT or NTFS, FAT32. That is, to use any of them follows, taking into account the size of the media, its type, as well as the OS version on which the drive is predominantly used.

File Systems for Mac

Another popular hardware and software platform on the world market of computer equipment is Macintosh from Apple. The PCs of this series are running the operating system Mac OS. What are the features of organizing the work with files on Mac computers? Apple's most modern PCs use the Mac OS Extended file system. Previously, in Mac computers, data management was managed in accordance with HFS standards.

The main thing that can be noted in terms of its characteristics: a disk that is managed by the Mac OS Extended file system can accommodate very large files - it can be about several million terabytes.

File system on Android devices

The most popular OS for mobile devices - the form of electronic technology, not inferior to the popularity of PCs - is Android. How do you manage files on devices of the appropriate type? Let's note first of all that this operating system is actually a "mobile" adaptation of the Linux OS, which, thanks to the open software code, can be modified with the prospect of using on the widest range of devices. Therefore, the management of files in mobile devices running Android is implemented in general on the same principles as in Linux. Some of them we noted above. In particular, file management in Linux is done without dividing the media into logical disks, as it does in Windows. What else interesting is the Android file system?

The root directory on Android, as a rule, is the data area, called / mnt. Accordingly, the address of the desired file may look something like this: /mnt/sd/photo.jpg. In addition, there is another feature of the data management system that is implemented in this mobile OS. The fact is that the flash memory device is usually classified into several sections, such as, for example, System or Data. In this case, the initial size of each of them can not be changed. An approximate analogy regarding this technological aspect can be found, remembering that you can not (unless you use special software) to change the size of logical disks in Windows. It must be fixed.

Another interesting feature of the organization of working with files on Android - the corresponding operating system, as a rule, writes new data to a specific area of the disk - Data. Work, for example, with the System section is not carried out. Therefore, when the user activates the function of resetting the software settings of the smartphone or tablet to the level of "factory", in practice this means that those files that are written into the Data area are simply deleted. The System section, as a rule, remains unchanged. Moreover, any user can not make any adjustments to the content in the System without having specialized software. The procedure for updating the system area of the media on an Android device is called a flashing. This is not formatting, although both operations are often performed simultaneously. Typically, flashing is used to install on a mobile device a newer version of the Android OS.

Thus, the key principles on the basis of which the Android file system works is the lack of logical disks, as well as a strict delineation of access to system and user data. It can not be said that this approach is fundamentally different from what is implemented in Windows, however, according to many IT experts, in the OS from Microsoft for users there is somewhat greater freedom in working with files. However, as some experts believe, this can not be considered an unambiguous advantage of Windows. Of course, not only users, but also computer viruses, to which Windows is very susceptible (unlike Linux and its "mobile" implementation in the form of Android), of course, use the "Liberal" mode in the aspect of file management. In this, according to experts, is one of the reasons that the viruses for Android-devices are so few - purely from the technological point of view, they can not fully function in an operating environment that operates on the principles of strict control of access to files.