File system - what is it? File system NTFS, FAT, RAW, UDF. File system NTFS

When you format internal storage, external hard disk, flash drive, or SD card, Windows will prompt you to select the file system FAT32, ExFAT and NTFS. But in this window there is no description of what this file system means and what the difference is between them. Therefore, in today’s article we will try to decipher these file system names.

FAT32 is the oldest file system and was introduced in Windows 95 to replace FAT16.

The age of this file system has advantages and disadvantages. Almost all flash drives you buy are purchased with the FAT32 file system, for maximum compatibility not only with computers, but also with game consoles, and other devices that support flash drives.

Limitations of this age: file size larger than 4GB FAT32 is not supported, so you can upload any number of files to the drive, but each of them should not be larger than 4GB. The maximum partition size in FAT32 is 8TB, but in Windows operating systems the size of the created partition in this file system does not exceed 32GB. Although if you create a partition larger than 32GB on another system, then Windows will work with the drive. But again, if you create a partition in FAT32 larger than 32GB, then according to Microsoft the performance of this disk drops significantly.

While this file system is good for flash drives, and other external drives, for internal drives this system not very good. It lacks the permissions and other security features built into the more modern NTFS file system. To install a modern Windows operating system, you need to create a partition only in NTFS.

Compatibility: Supported by all versions of Windows, Mac, Linux, game consoles and other USB devices.

Restrictions: Maximum file size 4GB, 8TB maximum size section. IN Windows partition You can create no more than 32GB.

Ideal for: on removable drives for compatibility with most devices as long as you use files up to 4GB.

NTFS is the modern file system that Windows works with. All Windows operating systems format the partition to NTFS during installation. First appeared with Windows XP.

This type of file system is packed with other modern features. It supports file permissions for security, change logging, which can help you quickly recover errors if your computer suddenly reboots. It also supports shadow copies For backup, encryption, and other necessary functions.

To install a Windows system, your partition must be NTFS, and it is better to format secondary disks in this file system, for normal operation all applications.

But this file system is not compatible with other operating systems. It will work with all versions of Windows, but Mac OS X can only read disks in this file system, it cannot write to them. Also, Linux only reads NTFS partitions, although some distributions include write support. Most game consoles do not support NTFS, for example Sony PlayStation does not support this file system, and the Xbox 360 does not support it.

Compatibility: works with all versions of Windows, only reads on Mac, also Linux only reads, and not every distribution writes. Other devices are not supported by most.

Restrictions:

Ideal for: For system disk, and other internal drives that will only be used in Windows.

ExFat was introduced by Microsoft in 2006, and is otherwise called FAT64. Support for this file system was added with updates to Windows XP.

This file system is optimized for flash drives. One of the innovations of ExFat is the reduction in the number of overwrites of the same sector, which reduces wear on the drive.

Like NTFS, ExFat is not limited in file and partition sizes. In other words, if your drive is formatted in ExFat, then you can write files larger than 4GB to it. This file system best choice for drives where you want a lightweight file system with no file size restrictions.

ExFat is also more compatible than NTFS if the Mac only supported read NTFS, then it fully supports ExFat, both reading and writing. ExFat can also be accessed on Linux by installing additional software.

While ExFat is more friendly with operating systems, it is often not compatible with digital cameras, and not in all game consoles support this file system. Yes, and other older devices may be limited to supporting only FAT32.

Compatibility: Works in all versions of Windows, including modern ones Mac versions OS X, but requires additional software on Linux. Most older devices do not support this file system.

Restrictions: There are no restrictions on file sizes or partition sizes.

Ideal for: For USB flash drives, external drives, etc., if you work with files larger than 4GB, and if you want to reduce wear on the drive.

NTFS is ideal for internal drives, while ExFat is more suitable for flash drives. Fat32 is mainly used for older devices that do not support other file systems.

That's all for today, if you have any additions - write comments! Good luck to you :)

• NTFS is the main file system of the Windows NT family;
• FAT (File Allocation Table) is a simple file system used by Windows for flash memory devices, as well as for compatibility with other operating systems when installed on multi-boot disks. The main element of this file system is the FAT file allocation table (after which the entire file system is named), which is necessary to determine the location of the file on the disk. There are three variants of FAT, differing in the bit depth of the identifiers indicating the location of the files: FAT12, FAT16 and FAT32;
• exFAT (Extended FAT) is a development of the FAT file system that uses 64-bit identifiers. Mainly used for flash memory devices;
• CDFS (CD ROM File System) is a file system for CD disks that combines ISO formats 9660 1ISO 9660 – ISO (International Organization for Standardization) standard for CD file systems and Joliet 2 Joliet is an extension of the ISO 9660 standard developed by Microsoft. Removes strict restrictions on file naming ;
• UDF (Universal Disk Format) is a file system for CDs and DVD discs, designed to replace ISO 9660.

For further discussion, you need to know the following important concepts: disk, partition, simple and spanned volumes, sector, cluster.

Disk (disk) – device external memory , For example, hard drive or optical disc (CD, DVD, Blu ray).

Section (partition) – continuous part hard drive. A disk can contain multiple partitions.

Volume (volume) or logical disk (logical disk) – an area of ​​external memory with which operating system works as a single whole. Volumes can be simple or compound.

Simple volume – a volume consisting of one partition.

Multipartition volume – a volume consisting of several partitions (not necessarily on one disk).

Section concepts and simple volume differ: firstly, sections are formed mainly only on hard drives, and volumes are created on other external memory devices (for example, on optical disks and flash memory devices), secondly, the concept of “partition” is associated with physical device, and the concept of “volume” – with the logical representation of external memory.

Sector ( sector ) – a fixed-size data block on disk; the smallest unit of information for a disk. Typical sector size for hard drives equals 512 bytes, for optical disks– 2048 bytes. The disk is divided into sectors once during the disk creation process. low level formatting and usually cannot be changed.

Cluster is a logical block of data on a disk that includes one or more sectors. The number of sectors that make up a cluster is usually a multiple of powers of two. The cluster size is set by the operating system during the process high level formatting which can be carried out repeatedly.

When written to disk, the file will always occupy an integer number of clusters. For example, a 100 byte file on a file system with a 4 KB cluster size will occupy exactly 4 KB.

The choice of cluster size is related to the following considerations. Small clusters reduce the size of virtually unused disk space, which arises due to the placement of the file in a whole number of clusters. But at the same time, the total number of clusters on the disk increases and the size of the file system service structures in which information about files is stored increases.

NTFS Features

File system NTFS (New Technology File System) was developed by Microsoft in the early 1990s. as the main one file system for server versions of Windows operating systems. NTFS was introduced in 1993 in the operating room Windows system NT 3.1.

Currently, NTFS is seen as the file system of choice for both server and client versions of Windows.

NTFS uses 64-bit cluster IDs, so theoretically an NTFS volume can contain 264 clusters (16 EB3 2 10 bytes = 1 kilobyte (KB), 2 20 bytes = 1 megabyte (MB), 2 30 bytes = 1 gigabyte (GB), 2 40 bytes = 1 terabyte (TB), 2 50 bytes = 1 petabyte (PB), 2 60 bytes = 1 exabyte (EB), 2 70 bytes = 1 zettabyte (ZB).). However, current Windows implementations only support 32-bit cluster addressing, which, with a maximum cluster size of 64 KB (216 bytes), allows an NTFS volume to reach a size of up to 256 TB:

2 32 * 2 16 bytes = 2 48 bytes = 2 8 * 2 40 bytes = 256 TB.

For volumes larger than 4 GB, when formatting Windows suggests a default cluster size of 4 KB.

Let's list some of the features of NTFS [, p. 761]:

• recoverability – the ability of a file system to return to a working state after a failure occurs. This possibility is realized, firstly, due to the support of atomic transactions, and secondly, due to the redundancy of information storage. An atomic transaction is an operation on the file system that results in a change to the file system, which either succeeds completely or fails at all (i.e., if an atomic transaction fails, all changes are rolled back). Redundancy is used when storing the most important file system data that is critical for its correct operation;
• security – protection of files from unauthorized access. It is implemented using the Windows security model, discussed in Lecture 9 “Security in Windows”;
• encryption - converting a file into an encrypted code that cannot be read without a key. Conventional security mechanisms, such as assigning user access rights to files, do not fully protect information, for example, if the disk is moved to another computer. An operating system administrator can always access other users' files, even on an NTFS volume. Therefore, NTFS includes support for the Encrypting File System (EFS), which makes it easy to encrypt and decrypt files;
• RAID support (Redundant Array of Inexpensive (Independent) Disks - an array of inexpensive (independent) disks with redundancy) - the ability to use several disks to store information; data from one disk is automatically copied to others, thereby ensuring increased reliability;
• disk quotas for users (Per-User Volume Quotas) – the ability to allocate specific disk space (quotas) for each user; NTFS does not allow the user to write data to the disk in excess of the allocated quota.

NTFS structure

The structure of an NTFS volume is shown in Fig. 17.1.

Rice. 17.1.

At the beginning of the volume is boot record volume (Volume Boot Record), which contains the code Windows boot, volume information (in particular, file system type), addresses system files($Mft and $MftMirr – see below). The boot record usually takes up 8 KB (first 16 sectors).

In a certain area of ​​the volume (the address of the beginning of this area is indicated in the boot record) the main NTFS system structure is located - the master file table (Master File Table, MFT). The entries in this table contain all the information about the location of files on the volume, and small files are stored directly in MFT entries.

Important NTFS feature is that all information, both user and system, is stored in the form of files. System file names begin with the "$" sign. For example, the volume boot record is contained in the file $Boot, and the master file table is contained in the file $Mft. This organization of information allows you to work uniformly with both user and system data on the volume.

Because the MFT is a critical system structure that is accessed most frequently during volume operations, it is advantageous to store the $Mft file in a contiguous area logical drive to avoid its fragmentation (placement in different areas of the disk), and, therefore, increase the speed of working with it. For this purpose, when formatting a volume, a contiguous area called a zone is allocated.

The operating system, in addition to all other tasks, fulfills its main purpose - it organizes work with data according to a certain structure. The file system is used for these purposes. What FS is and what it can be, as well as other information about it will be presented below.

General description

The file system is a part of the operating system that is responsible for placing, storing, deleting information on media, providing users and applications with this information, as well as providing it safe use. In addition, it helps in data recovery in case of hardware or software failure. This is why the file system is so important. What is FS and what can it be? There are several types:

For hard drives, that is, random access devices;

For magnetic tapes, that is, devices with sequential access;

For optical media;

Virtual systems;

Network systems.5

The logical unit of data storage in a file system is a file, that is, an ordered collection of data that has a specific name. All data used by the operating system is presented in the form of files: programs, images, texts, music, videos, as well as drivers, libraries, etc. Each such element has a name, type, extension, attributes, and size. So, now you know, the File System is a collection of such elements, as well as ways to work with them. Depending on the form in which it is used and what principles are applicable to it, several main types of FS can be distinguished.

Software approach

So, if we are considering a file system (what it is and how to work with it), then it should be noted that this is a multi-level structure, on its upper level there is a file system switch that provides an interface between the system and specific application. It converts requests to files into a format that is perceived by the next level - drivers. They, in turn, contact the drivers specific devices, which store the necessary information.

Client-server applications have quite high requirements for file system performance. Modern systems are designed to provide efficient access, support for large-volume media, protect data from unauthorized access, and maintain the integrity of information.

File system FAT

This type was developed back in 1977 by Bill Gates and Mark McDonald. It was originally used in OS 86-DOS. If we talk about what the FAT file system is, it is worth noting that initially it was not capable of supporting hard drives, but only worked with flexible media up to 1 megabyte. Now this limitation is no longer relevant, and this FS was used by Microsoft for MS-DOS 1.0 and subsequent versions. FAT uses certain file naming conventions:

There must be a letter or number at the beginning of the name, and any ASCII character, in addition to space and special elements;

The name must be no more than 8 characters long, followed by a dot, and then the extension, which consists of three letters;

File names can use any case and are not distinguished or preserved.

Since FAT was originally designed for the single-user DOS operating system, it did not provide for storing data about the owner or access permissions. On at the moment This file system is the most widespread; most people support it to one degree or another. Its versatility makes it possible to use it on volumes that work with different operating systems. This is a simple FS that is not able to prevent file corruption due to incorrect shutdown of the computer. The operating systems running on its basis include special utilities, which check the structure and correct file inconsistencies.

File system NTFS

This FS is the most preferable for working with Windows NT OS, since it was developed specifically for it. The OS includes a convert utility that converts FAT and HPFS volumes to NTFS volumes. If we talk about what a file file is NTFS system, it is worth noting that it has significantly expanded the ability to control access to certain directories and files, introduced many attributes, implemented dynamic file compression tools, fault tolerance, and supports the requirements of the POSIX standard. In this FS you can use names up to 255 characters long, while short name it is generated in the same way as in VFAT. Understanding what the NTFS file system is, it is worth noting that if the operating system fails, it is capable of recovering itself, so the disk volume will remain accessible and the directory structure will not be affected.

Features of NTFS

On an NTFS volume, each file is represented by an entry in the MFT table. The first 16 table entries are reserved by the file system itself to store special information. The very first entry describes the file table itself. When the first record is destroyed, the second one is read for search mirror file MFT, where the first record is identical to the main table. A copy of the file is located in the logical center of the disk bootstrap. The third entry in the table contains a log file that is used for data recovery. The seventeenth and subsequent entries of the file table contain information about the files and directories that are on the hard drive.

The transaction log contains the full set of operations that change the structure of the volume, including file creation operations, as well as any commands that affect the directory structure. The transaction log is for NTFS recovery as a result of a system failure. The root directory entry contains a list of directories and files that are located in the root directory.

Features of EFS

The Encrypting File System (EFS) is a Windows component, with which information on the hard drive can be saved in an encrypted format. Encryption has become the strongest protection that this operating system can offer. IN in this case encryption for the user is quite simple action, this only requires checking a box in the properties of the folder or file. You can specify who can read such files. Encryption occurs when files are closed, and when they are opened, they are automatically ready for use.

RAW Features

Devices designed for storing data are the most vulnerable components, which are most often subject to damage not only physically, but also logically. Certain hardware problems can be fatal, while others have solutions. Sometimes users have a question: “What is the RAW file system?”

As you know, in order to write any information to a hard drive or flash drive, the drive must have a FS. The most common are FAT and NTFS. And RAW is not even a file system as we usually imagine it to be. In fact, this is a logical error already installed system, that is, its virtual absence for Windows. Most often, RAW is associated with the destruction of the file system structure. After this, the OS does not simply access the data, but also does not display technical information by equipment.

Features of UDF

Universal disk format(UDF) is designed to replace CDFS and add support for DVD-ROM devices. If we talk about what it is, this is a new implementation old version for which it meets the requirements. It is characterized by certain features:

File names can be up to 255 characters long;

The name can be lowercase or uppercase;

The maximum path length is 1023 characters.

Starting with Windows XP, this file system supports reading and writing.

This FS is used for flash drives that are supposed to be used when working with different computers, running different operating systems, in particular Windows and Linux. It was EXFAT that became the “bridge” between them, since it is capable of working with data received from the OS, each of which has its own file system. What it is and how it works will become clear in practice.

Conclusions

As is clear from the above, in each operating system specific file systems are used. They are designed to store ordered data structures on physical media information. If you suddenly have a question while using your computer about what a final file system is, then it is quite possible that when you tried to copy a certain file to the media, you received a message about exceeding the allowed size. That is why it is necessary to know in which FS what file size is considered acceptable, so that you do not encounter problems when transferring information.

At Windows installation XP, you will be prompted to format the existing partition on which the OS is installed to the NTFS file system. So what is it?

The NTFS file system provides a combination of performance, reliability, and efficiency that FAT cannot achieve. The main design goals of NTFS were to provide high-speed performance of standard file operations, such as reading, writing, searching, and to provide additional capabilities, including repairing a damaged file system on extremely large disks.

The NTFS file system is “its own” file system for Windows NT, and as WinXP is known, it is a kind of continuation of this line of OS. But if you are going to use several operating systems such as Windows 9x and Windows XP on one computer, then the boot volume cannot be formatted in NTFS, since the Windows 95 (98) lines “understand” only FAT, and disks formatted in NTFS for these The OS simply doesn't exist. Files located on NTFS drives can only be seen using third-party programs. If during installation you did not format the partition in NTFS, then this can be done after it. In the WindowsXP command line you need to type "Convert (drive name)/FS:NTFS" without quotes.

Below is comparison table file FAT systems and NTFS

NTFS has security characteristics, supporting data access control and owner privileges that play exclusively important role in ensuring the integrity of important data. Folders and NTFS files can have access rights assigned to them regardless of whether they are shared or not.
NTFS is the only file system in Windows that allows you to assign permissions to different files. By setting users specific permissions on files and directories, the user can protect sensitive information from unauthorized access. User permissions to access file system objects work on the principle of addition. This means that effective permissions, that is, those permissions that the user actually has on a particular directory or file, are formed from all direct or indirect permissions assigned to the user for of this object using the logical "Or" function. For example, if a user has the right to assign read permission to a directory, and is indirectly given write permission through group membership, then the result is that the user will be able to read information in the directory files and write data to them.
To assign permission to a user or group to access specific file you need to: 1. Select the file with the mouse and press the right button. Select the Properties item from the context menu. In the file properties window that appears, go to the Security tab. By default, this tab is not there; for it to appear, you need to uncheck Simple File Sharing in the folder properties (use simple general access to files).
2. The Name group shows a list of users and groups that have already been granted permissions for this file. To add or remove users or new groups, click the Add/Remove button. The Select Users, Groups dialog box will appear. In the Enter the object names to select field, Enter the object names to select. write the user name, the Check Names button allows you to check the correct spelling of the name.
3. In the Permissions group, permissions are set. There are Deny and Allow indicators. The following options are checked: Full Control - the user has unlimited access to the file, Modify - the user can modify the file, Read & execute, Read - the user can only read the file, Write - The user can write to the file.

For more fine tuning permissions, you must click the Advanced button. The Advanced Security Settings for dialog box appears. Here you can optionally specify additional permissions, configure audit policies, change (view) file owner information, and add/remove users who can access the file.
The next thing is very useful property The NTFS file system is the ability to introduce quotas. This property is usually necessary for system administrators of large companies where a large number of users work, who do not have the habit of keeping information up to date, and who store unnecessary files, thereby taking up disk space. Since the administrator cannot monitor all this, he can impose a disk usage quota on a specific user. Once quotas are set, a user can store a limited amount of data on a volume, while the disk can remain free space. If the user exceeds the quota assigned to him, a corresponding entry will be made in the event log. To enable quotas on a disk, you must first of all be in NTFS format, then in the properties of the Tools-Folder Options-View folder, uncheck the Simple File Sharing checkbox. This is necessary for the Quota tab to appear in the disk properties. In it, you need to check the Enable quota managment checkbox. This will set a soft quota, which will issue a warning that the user, if this happens, has exceeded the quota, but he will have the right to write. To deny access to this volume to a user if the quota is exceeded, you must select the Deny disk space to users exceeding quota limit check box. On the same tab, you can set the size of the allocated quota (Limit disk space to) and the threshold, exceeding which causes a warning to be written in the event log (Set Warning level to) - Set the threshold for issuing a message. These settings are set by default for all users. In the Quota Entries window, you can change the parameters of the quota set for a specific user. To do this, select the configurable account, use the context menu to select properties and configure the quota.
And one more innovation in NTFS 5 - mount points. The user can define various, unrelated folders and even drives in the system as one drive or folder. This is of great importance for identifying in one place the heterogeneous information located in the system. Files and folders created in this way have a unique identification number, which guarantees their correct location in the system, even if the folder or file has been moved.