What is a file system and how to find out the type of file system on a disk. File organization and access. The concept of asynchronous input-output. Overview of Common File Systems
Beginner users often have no idea at all about the partitions of their hard drive and the logical drives of the hard drive. At first, this does not interfere with their work on the computer at all, although it does not allow them to use it more productively. But sometimes you have to deal with more important things, and then ignorance of simple rules can result in serious problems, including complete inoperability of the operating system and loss of important data.
In fact, it is enough to remember a few simple things and keep this information in mind during any actions with hard drive partitions.
What is a section
Let me start with the fact that a new, freshly purchased hard drive is completely unsuitable for work without prior preparation. In order to be able to save and read data on it, you must first create special “storages” for this data - partitions, and prepare these “storages” for “warehousing” and storing your files - format them, i.e. create a file system on them. As soon as at least one partition is created and formatted, it can already be used.
Sometimes it happens that a hard drive has only one partition that occupies the entire hard drive. This can be observed especially often among beginners who have just bought a computer. This option is the simplest, but also the most unsuccessful, because... both the operating system and your data are stored in one place, and if there are any problems with the operating system, or when reinstalling the OS, you risk losing everything at once.
A more practical option is when the hard drive is divided into several partitions - at least two. One partition contains the operating system itself, and the other stores your files. In this case, if there are problems or reinstallation of the operating system, only the partition on which it was located will be affected. Everything else will remain untouched.
In addition, dividing into several sections will allow you to more conveniently organize file storage - you can, for example, allocate a separate section for music or video if you have a lot of them; or if you often work with torrents, you can allocate a separate piece of your hard drive for them.
It also simplifies computer maintenance - for example, it is much easier and faster to defragment several relatively small sections in turn than to defragment one huge piece. The same applies to scanning a disk with an antivirus.
In general, we figured it out with convenience - here everyone is free to invent themselves to the best of their needs. However, there are several simple rules, violation of which can result in complete loss of data.
I'll start in order.
Rule #1
On just one hard drive there can be no more than 4 main sections, less is possible, more is not. These requirements do not depend on any operating system - they are dictated by the current level of development of computer electronics. And it will not be possible to overcome them yet. If more than 4 sections are required, then another rule comes into force.
It was not in vain that I mentioned MAIN sections - this is not just a word, it means one of two types of sections. In addition to the main one, the section can also be additional (extended). And in this regard, the rule about 4 partitions is somewhat transformed - on one hard drive there can be up to 4 main sections, or up to 3 main sections plus one additional(there can only be one extended partition on a disk).
What does this give us? The fact is that an additional (extended) partition is, in fact, a container within which you can create an UNLIMITED number of logical disks. And for the user there will be absolutely no difference between working with the main partition and working with a logical disk. Thus, by creating an extended partition and logical drives inside it, we can divide the hard drive to suit our needs as we need it.
Please note that if you delete an extended partition, all logical drives included in it will also disappear.
Rule #2
One of the sections is required it should be active (in Linux - have a flag boot). It is on it that the boot files that will launch the operating system are located. The system itself may be located in another place, but the files from which it starts are only there.
Most often, the first partition of the hard disk becomes active (disk C:/ on Windows), but it's not required condition. In addition, you can always manually reassign any other main partition as active, but you should not forget to move the boot files there, otherwise the operating system will not start.
Rule #3
If you are going to install several operating systems on one computer, then each of them should be installed on a separate partition ( theoretically, you can put it in one, but subsequent problems after this cannot be avoided). OS Windows family can only be installed on primary partitions. Accordingly, if you are going to install two Windows in multiboot mode, then they will occupy two main partitions. Linux operating systems do not have such a limitation and can be installed anywhere.
File systems
Before using a partition, you need to format it - create a file system on it (partition it in a special way).
There are quite a few file systems now. a large number of, and all have different characteristics.
Operating systems of the Windows family can only work with FAT, FAT32 and NTFS file systems.
FAT is a very outdated system, and its use today is hardly justified. FAT32 more modern, but has serious limitations. which prevent its full use. For example, the maximum file size that FAT32 supports is about 4 GB. That is why, if you try, for example, to copy an image of a full-sized DVD disc to a flash drive ( which by default are formatted in FAT32) You will receive a message about lack of free space, although in fact there is still plenty of space. Because of this, using it on sections where video work occurs is almost impossible ( and it’s problematic to use it under the section with torrents).
The best choice for running Windows today would be file system NTFS. It does not have such restrictions as FAT32, it has additional features to ensure security, more stable and reliable.
For UNIXes, which includes Linux, there are many more file systems. Each of them has its own advantages and disadvantages and is more suitable for certain tasks. The default on Linux is ext4, but you can use any other one. You can easily find information on which Linux file system is most suitable for your tasks on the Internet.
A few words about compatibility
Windows does not understand any file systems other than its own. Access from under it to Linux partitions was possible only with the help of special programs or a plugin for Total Commander. Unfortunately, a plugin for Windows has not yet been written for the most modern Linux file systems.
Linux has always understood FAT and FAT32 very well, and in the last 2-3 years it has been working without problems with NTFS through a special driver NTFS-3g, both for reading and writing. Plus, it supports most of the additional features of NTFS. So from Linux you will always have full access to Windows partitions.
It is worth mentioning various household appliances - DVD players, satellite receivers, etc. All this technique can only work with FAT and FAT32. NTFS, and even more so UNIX file systems ( with extremely rare exceptions) are completely incomprehensible to her. This should be remembered if you exchange data between such equipment and a computer.
Tools for work
A few words about the tools for working with partitions.
I'll start with Windows. It includes a standard tool Disk management. You can reach it through Control Panel, or by clicking right click mouse on icon My computer => Management and selecting in the left column Disk management.
Please note that three partitions in the screenshot are marked as unknown partitions. These are partitions with Linux - Windows sees them, but it cannot identify them, much less work with them.
also in Disk Management You can clearly see the main and additional sections, as well as the active section ( marked as System- it contains boot files; The OS itself is installed in a partition marked as - i.e. Windows swaps labels). Of all the features, this tool only provides creating and deleting partitions, as well as reassigning the active partition and changing drive letters ( in Vista and Windows 7 the functionality has increased slightly). If there is nothing else at hand, then sometimes this is enough.
Important to remember , What Disk management- the tool is inconvenient, ineffective and extremely dangerous, especially in inexperienced hands. It is assumed that the user who uses it knows absolutely exactly what he is doing, because... any changes are applied immediately, without question, and it is impossible to see in advance what certain actions will lead to.
Therefore, I advise using it only in extreme cases.
They have much greater capabilities, convenience and safety. various programs from the cohort Partition Magic-ov, for example, . There are quite a large number of such programs, they are all different and in last years many of them changed owner-developers and their name. Therefore, if you decide to choose one of them, you will have to worry about searching on your own on the wide expanses of the Internet. This is not difficult, especially since the leaders in this field can be counted on one hand.
Acronis Disk Director Suite
In my opinion ( exclusively on mine - because Many people may have a different opinion on this matter.), the most powerful and convenient program for working with a hard drive and partitions is.
The program is Russian (although occasionally you come across variants with English language) and very easy to use. At the same time, it fully provides the entire range of possible operations with the hard drive. In addition, almost all of your actions on partitions occur without losing the information located on them.
All operations that you perform on partitions are instantly displayed in graphically so that everything can be assessed visually. But the actions themselves are not performed - only after you evaluate everything yourself, and the result completely and completely satisfies you, you can press the button " Apply". Up to this point, you can undo all actions step by step.
If several hard drives are connected to the computer, they will all be shown in the program window - one above the other. The main sections are marked with green flags, and the active section is marked with a red flag.
In addition, when starting Acronis Disk Director Suite offers a choice of two operating modes - automatic, in which all operations can be carried out with the help of “masters”, and manual mode, in which all power is given to the user. The second mode, IMHO, is more convenient and flexible, but beginners can also use automatic.
The program also contains a complete and very detailed help.
One more possibility should be mentioned - from the program window you can create and burn a special boot disk that will contain files Acronis Disk Director Suite. This thing is very convenient and extremely useful in the household - after all, having this disk, there is completely no need to install the program itself and even have an operating system. From this disk you can boot your computer and perform any operations with partitions.
Now about the unpleasant stuff. It lies in the fact that the program is updated relatively rarely, so sometimes situations arise when the most modern hard drives she can't work. This applies to a greater extent to its version on the boot disk, because If Acronis Disk Director Suite installed in the operating system, then to work with the disk it will use drivers from Windows kit. She also has some problems with Unix file systems - she does not understand most modern file systems ( this can be seen in the provided screenshot), although it works great with the old classic ones.
Came out the other day a new version Acronis Disk Director Suite for English-speaking users (there is no new Russian version yet), which already works with the newest hard drives without any problems. But the problems with modern Unix file systems have not yet been resolved.
GParted
Another powerful and versatile tool for working with a hard drive is the program GParted from the Linux kit.
It can be found on almost all Linux Live-CDs.
The story about the program’s capabilities can be summed up in one phrase: “Almost everything can be done.” The interface is simple and unpretentious, and the work is absolutely transparent and understandable. All your actions are also first displayed visually, and are performed only after pressing a special button, when you decide that you are satisfied with everything.
Besides, GParted supports a much larger number of file systems, including the most modern ones.
If you have several hard drives, only one will be shown in the program window at a time. To work with others, use the drop-down list on the panel (on the right), which lists all connected hard drives.
GParted cannot work with partitions that are currently mounted (a warning icon will appear opposite such a partition). To perform any actions with such partitions, you will first have to unmount them.
A few notes about the programs that are included in operating system installers and can be used when installing the OS.
When installing Windows, all partitions of the hard drive will be seen exactly the same, without division into primary and extended. The only differences will be in the marks and sizes, and it is extremely easy to get confused. Therefore, it is advisable to use it only if you are installing an operating system on a new hard drive for the first time. If your disk has already been used and there is any information on it, it is best to take care of everything in advance in a third-party program, and reduce the actions in the installer only to selecting the desired partition and formatting (if necessary).
The situation is similar when installing Linux. Although everything is defined correctly there, it is not displayed very clearly, and the work occurs less transparently than in the same GParted.
So it's best to create partitions before installation the right size in the right place and format them into any Linux file system, and when installing the OS, ignoring the proposed automatic options and choosing manual partitioning, simply mount them in the right places and, if necessary, change the file system to another by simply checking the box Format opposite their sections.
For greater clarity, I recommend carefully studying the screenshots for the article ( screenshots are clickable - when you click on them, full-size pictures will open in separate tabs). Please note that everywhere is depicted THE SAME hard drive only different programs. On this disk, two operating systems are installed in parallel in multiboot mode - Windows and Linux, which coexist quite peacefully on one computer. Each operating system is allocated 3 sections ( separation is not ideal, but quite acceptable). Look carefully at what it looks like in each program.
The file system determines how data will be stored on the disk, and what principles of access to stored information can be used when reading it.
We are accustomed to perceiving information on our PC in the form of specific files, neatly (or not so :)) arranged in folders. Meanwhile, your computer works with data on a completely different principle. There are no solid files for it on the hard drive. It “sees” only clearly addressed sectors with bytecode. Moreover, the code of one file is not always stored in adjacent sectors (so-called data fragmentation).
How does the computer “understand” where, for example, it should look for our text document, which lies, say, on the Desktop? It turns out that he is responsible for this file system hard drive. And today we will find out what file systems are and what their features are.
What is a file system
To understand what a file system is, it is best to use the method of analogies. Let's imagine that the hard drive is a kind of box in which multi-colored cubes are stored. These cubes are parts different files, stored in limited-sized cells called clusters. They can be simply piled up in a heap or have a certain order of placement. So, if these conditional cubes are stored not in a chaotic pile, but in accordance with some kind of logic, we can talk about the presence of some kind of analogue of a file system.
The file system determines the order in which data is stored on the disk and the principles for accessing it; however, the type of file system largely depends on the type of media. For example, it is obvious that for magnetic tape, which supports writing only sequential blocks of data, only a single-level file system with sequential access to clusters with information, and for a modern SSD disk - any multi-level with random access:
Based on the principle of the sequence of storing data blocks, file systems, as we have already seen, can be divided into those that store clusters with file fragments sequentially or arbitrarily. As for the levels, the FS can be divided into single-level And tree-like(multi-level).
In the first case, all files are displayed as a single flat list, and in the second - as a hierarchical list. In this case, the level of investments is, as a rule, unlimited, and branching comes either from only one ("root" in UNIX) or from several root directories (logical drives in Windows):
Features of file systems also include the presence of various mechanisms that protect the data structure from failures. One of the most modern mechanisms for ensuring FS fault tolerance is logging. It allows you to record all actions performed with files in special service files (they are called “logs” or “logs”).
Logging can be complete, when for each operation a backup is created not only of the state of the clusters, but also of all recorded data. Such logging is often used for various databases, but it significantly slows down the system and increases the size of the logs (in fact, the logs store a complete backup of the entire file system with all its data).
Logged much more frequently only logical operations and (optionally) the state of the file system clusters. That is, the log only records that, say, a file named "file.txt" with a size of 52 KB was written to such and such clusters. The contents of the file itself do not appear in the log. This approach allows you to avoid duplication of data, speeds up the process of working with files and significantly reduces the size of the log itself. The only drawback with this method of journaling is that if a failure occurs, the data being written may be lost (since there is no copy of it), but the state of the file system itself will remain operational.
Formatting
Since we are talking about file systems in the context of modern computers with their hard or SSD drives, we will pay more attention to multi-level file systems with random access to clusters. The most popular in the computer world today are: FAT32, NTFS, exFAT, ext3/ext4, ReiserFS and HFS+.
Changing the file system on the disk is achieved by formatting. It provides for the creation at the hard disk level in its initial sector of special service labels that define the principles of data access. In this case, clusters with existing data during formatting are usually cleared or marked as empty and available for overwriting. Exceptions are special cases file system conversion(for example, from FAT32 to NTFS), in which the entire data structure is preserved.
For formatting you can use regular means operating system (for example, Linux console commands or the disk context menu in Windows), functions available on preparatory stage OS installations, or special programs. The only thing to consider when software solution, is that your operating system may not support the file system you choose without installing additional drivers(eg ext3/4 on Windows):
There is also a concept low level formatting. Initially, it implied cleaning the disk and writing special service information to its clusters to align the read heads. For modern hard drives, this function is program level is no longer provided (this can only be done with the help of special equipment), however, the concept of low-level formatting has been preserved, although it has been slightly transformed.
It is now carried out using special software (HDD Low Level Format Tool for Windows) or commands (DD for Linux). When using it, all hard disk clusters are overwritten with zeros and any markup is completely destroyed. After this, the file system essentially disappears and appears in Windows as RAW. To access the drive after this formatting, you need to format it with one of the available higher-level traditional file systems.
Features of file systems
Well, now let's look at some features of the most common file systems.
FAT32
One of the oldest disk file systems that is still widely used today is FAT32(abbreviated English: “File Allocation Table” - “file allocation table”). Due to its prevalence, it is supported by the maximum number of all kinds of equipment, from car radios to powerful modern computers. Most flash drives sold today are also formatted in FAT32.
This FS first appeared in Windows 95 OSR2 in 1996, becoming a logical development of the even earlier FAT16 (1983). One of the main reasons for the transition to a new file system was the emergence of capacious (at that time) hard drives with a capacity of more than 2 GiB (gibibyte - a more accurate version of gigabyte (109) - 230 bytes) (the maximum possible partition size in FAT16). FAT32 allowed up to 268,435,445 clusters of a maximum of 32 KB, which is equivalent to 8 TiB per volume. However, if the cluster size is standard (512B), then the maximum volume size will be only slightly more than 127 GB.
The basis of FAT32, as its name suggests, is a file table. It stores records of existing files, as well as the time they were created and last accessed. There is no journaling, so reading/writing processes in this file system are faster than, for example, in NTFS, which keeps more complete logs. Exactly for the reason good performance FAT32 is still widely used today.
The main disadvantage of FAT32 on this moment The maximum file size limit is 4 GiB. Files exceeding this threshold must be split into parts, which in turn makes them difficult to access. In addition, FAT32 has some other limitations in Windows environment. For example, using standard tools you will not be able to create partitions larger than 32 GB. Therefore, flash drives of 64 GB or more will have to be formatted either using special software or on Linux.
However, in this case, although access to the media will be preserved, it will be hampered by “brakes” both when reading and writing data. Therefore, when using drives larger than 32 GB, it is better to format them in other file systems, such as exFAT or NTFS.
NTFS
If Windows line 95/98 continued the traditions of the already outdated operating room at that time DOS systems, That new line NT was initially focused on innovation. Therefore, with the advent of Windows NT 3.1 in 1993, a new file system was created specifically for it NTFS(abbreviated as "New Technology" File System" - "new technology file system").
This file system is still the main one for all modern versions of Windows, since it provides good operating speed, supports drives with a capacity of up to 16 EiB (exbibyte - 260) (with a maximum cluster size of 64 KB) without restrictions on file sizes and has in its arsenal pretty good functionality. For example, NTFS is a journaling file system and also supports the distribution of user roles for access to individual data, which was not the case in FAT32.
Like FAT32, NTFS is based on a table, but it is a more advanced database and is called MFT(abbreviated English: "Master File Table" - "master file table"). The rows in this table correspond to files stored on a particular partition, and the columns contain the attributes of these files (creation date, size, access rights, etc.).
In addition, to increase fault tolerance in NTFS, USN magazine(abbreviated English "Update Sequence Number" - literally "update order number"). This log, similar to the FAT32 table, records data about changes to a particular file. However, if the FAT32 table only recorded the time of the last access to the data, which did not provide any special practical benefits, then the USN can save the previous state of the file system, which allows it to be restored in case of failures.
One more NTFS feature is support alternative data streams(English: "Alternate Data Streams" - ADS). They were originally conceived to distinguish between the execution of various processes. Then (in Windows 2000) they were used to store some file attributes (author name, icon, etc.), similar to how it was done in HFS from MacOS. IN modern Windows alternative streams can store almost any information. Some viruses even use this to hide their presence in the system.
The fact is that alternative streams are not detected by Windows Explorer and, in fact, are invisible to users and most programs. However, you can view them and even use them, for example, to hide any data using special software. It is convenient to view data in alternative streams using the NTFS Stream Explorer program, and use them to hide files using Xp-lore:
Additional features that deserve mention for NTFS are support for encryption, data compression, “soft” and “hard” links to files (alas, there is no such option for folders), disk quotas for different system users, and also, of course, differentiation of access rights to files.
NTFS was originally created exclusively for Windows, however, today it is supported by most media players (flash drives can also be formatted in it), Linux and MacOS operating systems (although with some recording restrictions). It is worth noting, however, the weak NTFS support on popular gaming consoles. Of these, only Xbox One has support for it.
exFAT
With the increase in the volume of flash drives in the second half of the 2000s, it became clear that the commonly used FAT32 file system would soon exhaust its potential. Using journaled NTFS for flash drives with their limited number of rewrite cycles and slower operation turned out to be not entirely advisable. Therefore, in 2006, the same Microsoft corporation released a new file system exFAT(abbreviated "Extended FAT" - "extended FAT") bundled with the Windows Embedded CE 6.0 operating system:
It became a logical continuation of the development of FAT32, which is why it is sometimes also called FAT64. The main trump card of the new file system was the removal of restrictions on file sizes and an increase in the theoretical limit for a disk partition to 16 E&B (as in NTFS). At the same time, due to the lack of journaling, exFAT retained high data access speed and compactness.
Another advantage of exFAT was the ability to increase the cluster size to 32 MB, which significantly optimized the storage of large files (for example, video). In addition, data storage in exFAT is organized in such a way as to minimize the processes of fragmentation and rewriting of the same clusters. All this was done, again, for the sake of optimizing the operation of flash drives, for which the file system was originally developed.
Due to the fact that exFAT is a relatively new file system, there are some restrictions on its use. IN Windows full its support appeared only in Vista SP1 (although there is an update for Windows XP SP2 - ). MacOS supports exFAT since version 10.6.5, and for Linux you need to install separate driver(some distributions have it built-in, and some are read-only).
ext2, ext3 and ext4
If in the Windows environment NTFS has been ruling the roost for decades, then in the Linux camp there has traditionally been a very wide variety, including among the file systems used. True, there is one line of them that is used by most distributions by default. These are file systems of the family ext(English abbreviation "Extended File System" - "extended file system"), which since 1992 were initially created specifically for Linux.
The second version is the most widely used ext2, which, like NTFS, appeared back in 1993. True, unlike NTFS, ext2 is not a journaling file system. This is both its plus and minus. The advantage is that it is one of the fastest file systems for writing data. Also, the lack of logging makes it preferable to use it on flash drives and SSD drives. The price for performance is low fault tolerance.
In order to improve the stability of ext2, an improved version was developed in 2001 ext3. It introduced journaling, which can operate in three modes: “writeback” (only file system metadata is written), “ordered” (logging is always done BEFORE changing the FS) and “journal” (a full backup of metadata and the files themselves being changed).
Otherwise, there were no special innovations. And the speed of work, compared to previous version, decreased significantly, so already in 2006 a prototype of the next stage of file system development appeared ext4, the final release of which took place in 2008. The fourth extended file system retained journaling, but significantly increased data reading speed, which was even higher than in ext2!
Other innovations worth noting include an increase in the maximum volume of a disk partition to 1 EiB (from 32 TiB in ext2 and ext3), an increase in the maximum file size to 16 TiB (from 2 TiB in earlier versions) and the appearance of an extent mechanism (from the English "extent" - "space"). The latter allows you to access not single blocks, as is implemented in other file systems (and in ext3 in particular), but to combined disk spaces from sequential clusters, with a total volume of up to 128 MB, which significantly increases performance and reduces data fragmentation.
Today, support for file systems of the ext family of one version or another is present by default in almost all Linux systems. Of these, almost all systems released in 2010 and older support ext4. To access ext partitions in Windows and MacOS, you need to install special software and/or drivers.
ReiserFS
Another young and promising file system “originally” from the world of Linux is ReiserFS. Through the efforts of the team of American developer Hans Reiser, it became the first journaled file system to be added to the kernel Linux versions 2.4.1 in 2001, just before ext3 support was added.
In fact, like ext3, which appeared after it, ReiserFS made it possible to use Linux full or partial logging. However, unlike ext3, it had a larger allowable file size (up to 8 TiB versus 2) and a maximum file name length of 255 characters, not bytes (4032 bytes).
Also, one of the features of ReiserFS for which users fell in love with it was the ability to change the size of a partition without unmounting it. ext2 did not have such a function, but later it appeared in ext3, although ReiserFS was also the first in this regard.
Despite a number of advantages over alternative file systems of its time, ReiserFS was also not without its drawbacks. The most significant of them include rather weak fault tolerance in case of damage to the metadata structure and an ineffective defragmentation algorithm. Therefore, in 2004, work began to improve the file system, which became known as Reiser4.
True, despite a number of innovations, improvements and corrections, the new file system remained the preserve of a few enthusiasts. The fact is that in 2006, Hans Reiser committed the murder of his own wife and was taken into custody and later imprisoned. Accordingly, his company Namesys, which was developing Reiser4, was disbanded. Since then, support and modification of the file system has been carried out by a group of developers under the supervision of Russian developer Eduard Shishkin.
Ultimately, support for Reiser4 has not yet been added to the Linux kernel, but ReiserFS is available. Therefore, many continue to use it in various assemblies as the default file system.
HFS
Speaking about file systems characteristic of various operating systems, one cannot fail to mention MacOS with its HFS(abbreviated English: "Hierarchical File System" - "hierarchical file system"). The first versions of this system appeared back in 1985 along with the Macintosh System 1.0 operating system:
By modern standards, this file system was very ineffective, so in 1998, along with MacOS 8.1, its improved version called HFS+ or Mac OS Extended, which is supported to this day.
Like its predecessor, HFS+ divides the disk into 512 KB blocks (by default), which are combined into clusters responsible for storing certain files. However, the new FS has 32-bit addressing (instead of 16-bit). This allows you to avoid restrictions on the size of the written file and provides support for a maximum volume size of up to 8 E&B (and in the latest revisions up to 16 E&B).
Other advantages of HFS+ include journaling (an entire hidden volume called HFSJ is allocated for it), as well as multithreading. Moreover, if in NTFS alternative streams do not have particularly clear regulations on the types of stored information, then in HFS+ two streams are specifically distinguished: a data stream (stores the main data of files) and a resource stream (stores file metadata).
HFS+ is almost ideal for traditional HDDs, however, like the ReiserFS discussed above, it does not have the most effective algorithms for combating data fragmentation. Therefore, with the spread of SSD drives and their introduction into Apple equipment, it is increasingly being replaced by the file system developed in 2016 APFS(abbreviated English " Apple File System" - "Apple File System"), which appeared in the desktop macOS High Sierra (10.13) and mobile iOS 10.3.
In many ways, APFS is similar to exFAT in terms of optimizing read/write processes, however, unlike it, it has journaling, supports the distribution of data access rights, has improved data encryption and compression algorithms, and can also work with volumes up to 9 YB in size (don't laugh - "yobibyte") due to 64-bit addressing!
The only disadvantage of APFS is that it is only supported by modern Apple technology and is not yet available on other platforms.
Comparison of file systems
Today we looked at many different popular file systems, so it wouldn’t hurt to summarize all the data about them into a single table:
| Characteristics / FS | FAT32 | NTFS | exFAT | ext2 | ext4 | ReiserFS | HFS+ | APFS |
|---|---|---|---|---|---|---|---|---|
| Year of implementation | 1996 | 1993 | 2008 | 1993 | 2006 | 2001 | 1998 | 2016 |
| Scope of application | Windows removable drives, Linux | removable drives, Windows Vista+, Linux | Linux, removable storage | Linux | Linux | MacOS | MacOS | |
| Maximum file size | 4 GiB | 16 E&B | 16 E&B | 2 TiB | 16 TiB | 8 TiB | 16 E&B | 9 YiB |
| Maximum volume size | 8 TiB | 16 E&B | 64 ZiB (zebibyte) | 32 TiB | 1 E&B | 16 TiB | 16 E&B | 9 YiB |
| Logging | - | + | - | - | + | + | + | + |
| Access rights management | - | + | - | - | + | + | + | + |
conclusions
As you can see, each operating system has its own optimal file system, which allows you to work with data most efficiently. For example, for Windows it is NTFS, for MacOS it is HFS+ or APFS. The only exceptions to the rule can be considered numerous Linux distributions. There are more than a dozen file systems, each with its own advantages and disadvantages.
Most Windows users should remember only the three most common FS: FAT32 - for small flash drives and old equipment, NTFS - for most computers and exFAT - for capacious flash drives and external SSD drives (about the relevance of formatting system disk exFAT is still controversial due to the lack of journaling and greater susceptibility to failures).
P.S. Permission granted to freely copy and quote this article provided that an open active link to the source is indicated and the authorship of Ruslan Tertyshny is preserved.
File system– this, on the one hand, data management system located on an external storage device. To organize data storage on an external device and access it when performing operations, the OS builds special tables and directories. Disk space can be organized in different ways. Therefore, on the other hand, file system– it’s ourselves data and service information, used to manage this data located on one device, organize its input and storage, and perform operations on it (one device - one file system). Method of organizing data storage on external devices depends on the file systems used in the OS.
Currently used in various Microsoft operating systems different types file systems. Each of them has its own characteristics, and, unfortunately, they may not be recognized by non-native operating systems.
The old FAT16 file system is recognized by all operating systems since MS-DOS, it is supported by Windows, Windows NT, OS/2 and Unix, but it is very inefficient and wastes a lot of disk space. FAT32 can cause problems when installing multiple operating systems on a PC. The table below shows the OS capabilities to support different file systems.
File system FAT designed for small disks and simple directory structures. The basis of its organization is the FAT table (File Allocation Table). This system is only effective on logical drives whose size does not exceed 256 MB. Disk space when storing data using FAT can only be allocated as whole clusters, That's why disk space may be wasted if the file being placed does not fill the entire last cluster allocated to it (for example, if the cluster size is 32 KB, then placing a 10 KB file on disk will not use the 22 KB of disk memory allocated to this file).
In the event of failures (for example, a sudden power outage), information about the location of the chain of clusters occupied by the file may be lost. The information in the FAT table may be corrupted. This can lead to the appearance of “garbage” on the disk – clusters that are unusable.
To restore the file system, the OS includes special utilities, which scan(check) the disk and search on it physical damage and errors in the file system.
The general disk size limitation when using FAT is 2 GB. Size is limited when using FAT root directory(512 files or folders, and even less if long names are used).
The FAT table is stored at the beginning of the disk. To increase the reliability of the work, a copy is created.
File system FAT32 provides advantages over the FAT implementation: drives up to 2 TB in size are supported; disk space is used more efficiently (clusters of 4, 8, 16 and 32 KB in size are used); the restriction on the size of the root directory is removed (it is stored, like all other folders and files, in the form of a chain of clusters); provides greater reliability and faster loading of programs.
The main goal in implementation NTFS file system(NT File System) was providing a combination high performance, reliability and efficiency. This system implements high-speed execution standard operations over files (search, read, write). NTFS supports data access control and owner privileges. In this system, you can assign rights (permissions) to access devices, folders and individual files.
The NTFS file system has the following additional features: disk activity logging (transaction log) allows you to quickly recover disks after failures (each I/O operation that changes a file is considered a transaction, i.e. an indivisible operation that must be completely completed, and in case of failure, the system rolls back to its beginning); flexible formatting options ensure more efficient use of disk space; compression options allow you to compress individual files and directories (for cluster sizes up to 4 KB); volumes can expand and use disk space not allocated to other partitions; striped volumes make it possible to speed up data access; Mirrored volumes and RAID-5 volumes provide fault-tolerant data storage.
The NTFS 5 file system provides new features: Windows supports distributed file system(DFS - Distributed File System), which allows you to combine all network resources, And encrypted file system(EFS - Encrypting File System), which is an add-on to NTFS, which complements it with data encryption capabilities.
Material for review lecture No. 33
for specialty students
"Information Technology Software"
Associate Professor of the Department of Computer Science, Ph.D. Livak E.N.
FILE MANAGEMENT SYSTEMS
Basic concepts, facts
Purpose. Features of file systemsFATVFATFAT 32,HPFSNTFS. File systems UNIX OS (s5, ufs), Linux OS Ext2FS. System areas of the disk (partition, volume). Principles of file placement and storage of file location information. Organization of catalogs. Restricting access to files and directories.
Skills
Using knowledge of the file system structure to protect and restore computer information (files and directories). Organization of access control to files.
File systems. File system structure
Data on disk is stored in the form of files. A file is a named part of a disk.
File management systems are designed to manage files.
The ability to deal with data stored in files at the logical level is provided by the file system. It is the file system that determines the way data is organized on any storage medium.
Thus, file system is a set of specifications and the corresponding software, which are responsible for creating, destroying, organizing, reading, writing, modifying and moving file information, as well as for controlling access to files and managing the resources that are used by files.
The file management system is the main subsystem in the vast majority of modern operating systems.
Using a file management system
· all system processing programs are connected using data;
· problems of centralized distribution of disk space and data management are solved;
· the user is provided with opportunities to perform operations on files (creation, etc.), exchange data between files and various devices, and protect files from unauthorized access.
Some operating systems may have multiple file management systems, giving them the ability to handle multiple file systems.
Let's try to distinguish between a file system and a file management system.
The term "file system" defines the principles of access to data organized in files.
Term "file management system" refers to a specific implementation of the file system, i.e. This is a set of software modules that provide work with files in a specific OS.
So, to work with files organized in accordance with some file system, an appropriate file management system must be developed for each OS. This UV system will only work on the OS for which it is designed.
For the Windows OS family, the main file systems used are: VFAT, FAT 32, NTFS.
Let's look at the structure of these file systems.
On the file system FAT The disk space of any logical drive is divided into two areas:
system area and
· data area.
System area created and initialized during formatting, and subsequently updated when the file structure is manipulated.
The system area consists of the following components:
· boot sector containing the boot record (boot record);
· reserved sectors (they may not exist);
· file allocation tables (FAT, File Allocation Table);
· root directory (ROOT).
These components are located on the disk one after another.
Data area contains files and directories subordinate to the root one.
The data area is divided into so-called clusters. A cluster is one or more adjacent sectors of a data area. On the other hand, a cluster is the minimum addressable unit of disk memory allocated to a file. Those. a file or directory occupies an integer number of clusters. To create and write a new file to disk, the operating system allocates several free disk clusters for it. These clusters do not have to follow each other. For each file, a list of all cluster numbers that are assigned to that file is stored.
Dividing the data area into clusters instead of using sectors allows you to:
· reduce the size of the FAT table;
· reduce file fragmentation;
· the length of file chains is reduced Þ faster access to the file.
However, too large a cluster size leads to inefficient use of the data area, especially in the case of a large number of small files (after all, on average half a cluster is lost for each file).
In modern file systems (FAT 32, HPFS, NTFS) this problem is solved by limiting the cluster size (maximum 4 KB)
The data area map is T file allocation table (File Allocation Table - FAT) Each element of the FAT table (12, 16 or 32 bits) corresponds to one disk cluster and characterizes its state: free, busy or a bad cluster.
· If a cluster is allocated to a file (i.e., busy), then the corresponding FAT element contains the number of the next cluster of the file;
· the last cluster of the file is marked with a number in the range FF8h - FFFh (FFF8h - FFFFh);
· if the cluster is free, it contains the zero value 000h (0000h);
· a cluster that is unusable (failed) is marked with the number FF7h (FFF7h).
Thus, in the FAT table, clusters belonging to the same file are linked into chains.
The file allocation table is stored immediately after the boot record of the logical disk; its exact location is described in a special field in the boot sector.
It is stored in two identical copies, which follow each other. If the first copy of the table is destroyed, the second one is used.
Due to the fact that FAT is used very intensively during disk access, it is usually loaded into the RAM (into I/O buffers or cache) and remains there for as long as possible.
The main disadvantage of FAT is its slow processing of files. When creating a file, the rule is that the first free cluster is allocated. This leads to disk fragmentation and complex file chains. This results in slower work with files.
To view and edit the FAT table you can use utilityDiskEditor.
Detailed information about the file itself is stored in another structure called the root directory. Each logical drive has its own root directory (ROOT).
Root directory describes files and other directories. A directory element is a file descriptor.
Each file and directory descriptor includes it
· Name
· extension
date of creation or last modification
· time of creation or last modification
attributes (archive, directory attribute, volume attribute, system, hidden, read-only)
· file length (for a directory - 0)
· reserved field that is not used
· number of the first cluster in the chain of clusters allocated to a file or directory; Having received this number, the operating system, referring to the FAT table, finds out all the other cluster numbers of the file.
So, the user launches the file for execution. The operating system looks for a file with the desired name by looking at the descriptions of the files in the current directory. When the required element is found in the current directory, the operating system reads the number of the first cluster of this file, and then uses the FAT table to determine the remaining cluster numbers. Data from these clusters is read into RAM, combining into one continuous section. The operating system transfers control to the file, and the program begins to run.
To view and edit the root directory ROOT you can also use utilityDiskEditor.
File system VFAT
The VFAT (virtual FAT) file system first appeared in Windows for Workgroups 3.11 and was designed for protected mode file I/O.
This file system is used in Windows 95.
It is also supported in Windows NT 4.
VFAT is the native 32-bit file system of Windows 95. It is controlled by the VFAT .VXD driver.
VFAT uses 32-bit code for all file operations and can use 32-bit protected mode drivers.
BUT, the file allocation table entries remain 12- or 16-bit, so the same data structure (FAT) is used on the disk. Those. f table formatVFAT is the same, like the FAT format.
VFAT along with "8.3" names supports long file names. (VFAT is often said to be FAT with support for long names).
The main disadvantage of VFAT is large clustering losses with large logical disk sizes and restrictions on the size of the logical disk itself.
File system FAT 32
This is a new implementation of the idea of using the FAT table.
FAT 32 is a completely self-contained 32-bit file system.
First used in Windows OSR 2 (OEM Service Release 2).
Currently, FAT 32 is used in Windows 98 and Windows ME.
It contains numerous improvements and additions over previous FAT implementations.
1. Uses disk space much more efficiently due to the fact that it uses smaller clusters (4 KB) - it is estimated that savings of up to 15%.
2. Has an extended boot record that allows you to create copies of critical data structures Þ increases the disc's resistance to damage to disc structures
3. Can use FAT backup instead of standard one.
4. Can move the root directory, in other words, the root directory can be in any location Þ removes the limitation on the size of the root directory (512 elements, since ROOT was supposed to occupy one cluster).
5. Improved root directory structure
Additional fields have appeared, for example, creation time, creation date, last access date, checksum
There are still multiple handles for a long filename.
File system HPFS
HPFS (High Performance File System) is a high-performance file system.
HPFS first appeared in OS/2 1.2 and LAN Manager.
Let's list main features of HPFS.
· The main difference is basic principles placement of files on disk and principles of storing information about the location of files. Thanks to these principles, HPFS has high performance and fault tolerance, is reliable file system.
· Disk space in HPFS is allocated not in clusters (as in FAT), but blocks. In the modern implementation, the block size is taken equal to one sector, but in principle it could be of a different size. (In fact, a block is a cluster, only a cluster is always equal to one sector). Placing files in such small blocks allows use disk space more efficiently, since the overhead of free space is on average only (half a sector) 256 bytes per file. Let's remember what larger size cluster, the more disk space is wasted.
· The HPFS system strives to arrange the file in contiguous blocks, or, if this is not possible, place it on the disk in such a way that extents(fragments) of the file were physically as close to each other as possible. This approach is essential reduces write/read head positioning time hard drive and wait time (delay between installing the read/write head on the desired track). Let us recall that in a FAT file the first free cluster is simply allocated.
Extents(extent) - file fragments located in adjacent sectors of the disk. A file has at least one extent if it is not fragmented, and multiple extents otherwise.
·Used method balanced binary trees for storing and searching information about the location of files (directories are stored in the center of the disk, in addition, automatic sorting of directories is provided), which is essential increases productivity HPFS (vs. FAT).
· HPFS provides special extended file attributes that allow control access to files and directories.
Extended Attributes (extended attributes, EAs ) allow you to store Additional information about the file. For example, each file can be associated with its unique graphic (icon), file description, comment, file owner information, etc.
C HPFS partition structure
At the beginning of the partition with HPFS installed there are three block controls:
boot block
· additional block (super block) and
· spare (backup) block (spare block).
They occupy 18 sectors.
All remaining disk space in HPFS is divided into parts from adjacent sectors - stripes(band - strip, tape). Each strip takes up 8 MB of disk space.
Each strip has its own sector allocation bitmap.The bitmap shows which sectors of a given band are occupied and which are free. Each sector of a data strip corresponds to one bit in its bitmap. If bit = 1, then the sector is busy, if 0, then it is free.
The bitmaps of the two lanes are located side by side on the disk, as are the lanes themselves. That is, the sequence of stripes and cards looks like in Fig.
Compare withFAT. There is only one “bitmap” (FAT table) for the entire disk. And to work with it you have to move the read/write heads across half the disk on average.
It is in order to reduce the time of positioning the read/write heads of a hard disk that in HPFS the disk is divided into stripes.
Let's consider control blocks.
Boot block (bootblock)
Contains the volume name, its serial number, BIOS parameter block and boot program.
The bootstrap program finds the file OS 2 LDR , reads it into memory and transfers control to this OS boot program, which, in turn, loads the OS/2 kernel from disk into memory - OS 2 KRNL. And already OS 2 KRIML using information from the file CONFIG. SYS loads all other necessary program modules and data blocks into memory.
The boot block is located in sectors 0 to 15.
SuperBlock(super block)
Contains
· pointer to a list of bitmaps (bitmap block list). This list lists all the blocks on the disk that contain the bitmaps used to detect free sectors;
· pointer to the list of defective blocks (bad block list). When the system detects a damaged block, it is added to this list and is no longer used to store information;
· pointer to directory band
· pointer to the file node (F -node) of the root directory,
· date of the last scan of the partition by CHKDSK;
· information about the stripe size (in the current HPFS implementation - 8 MB).
Super block is located in sector 16.
Spareblock(spare block)
Contains
· pointer to the emergency replacement map (hotfix map or hotfix -areas);
· pointer to the list of free spare blocks (directory emergency free block list);
· a number of system flags and descriptors.
This block is located in sector 17 of the disk.
The backup block provides high fault tolerance to the HPFS file system and allows you to recover damaged data on the disk.
File placement principle
Extents(extent) - file fragments located in adjacent sectors of the disk. A file has at least one extent if it is not fragmented, and multiple extents otherwise.
To reduce the time it takes to position the read/write heads of a hard disk, the HPFS system strives to
1) place the file in adjacent blocks;
2) if this is not possible, then place the extents of the fragmented file as close to each other as possible,
To do this, HPFS uses statistics and also tries to conditionally reserve at least 4 kilobytes of space at the end of files that are growing.
Principles for storing file location information
Each file and directory on the disk has its own file node F-Node. This is a structure that contains information about the file's location and its extended attributes.
Each F-Node occupies one sector and is always located close to its file or directory (usually immediately before the file or directory). The F-Node object contains
· length,
· first 15 characters of the file name,
· special service information,
· statistics on file access,
· extended file attributes,
· a list of access rights (or only part of this list, if it is very large); If the extended attributes are too large for the file node, then a pointer to them is written to it.
· associative information about the location and subordination of the file, etc.
If the file is contiguous, then its location on disk is described by two 32-bit numbers. The first number is a pointer to the first block of the file, and the second is the extent length (the number of consecutive blocks that belong to the file).
If a file is fragmented, then the location of its extents is described in the file node by additional pairs of 32-bit numbers.
A file node can contain information about up to eight extents of a file. If a file has more extents, then a pointer to an allocation block is written to its file node, which can contain up to 40 pointers to extents or, similar to a directory tree block, to other allocation blocks.
Directory structure and placement
Used to store directories stripe located in the center of the disk.
This strip is called directoryband.
If it is completely full, HPFS starts placing file directories in other stripes.
Placing this information structure in the middle of the disk significantly reduces the average read/write head positioning time.
However, a significantly greater contribution to HPFS performance (compared to placing the Directory Band in the middle of a logical disk) is made by using method balanced binary trees for storing and retrieving information about the location of files.
Recall that in the file system FAT the directory has a linear structure, not ordered in a special way, so when searching for a file you need to look through it sequentially from the very beginning.
In HPFS, the directory structure is a balanced tree with entries arranged in alphabetical order.
Each entry included in the tree contains
· file attributes,
· pointer to the corresponding file node,
information about the time and date of file creation, time and date of the last update and access,
length of data containing extended attributes,
· file access counter,
file name length
· the name itself,
· and other information.
The HPFS file system looks only at the necessary branches of the binary tree when searching for a file in a directory. This method is many times more efficient than sequentially reading all entries in a directory, which is the case with the FAT system.
The size of each block in terms of which directories are allocated in the current HPFS implementation is 2 KB. The size of the entry describing the file depends on the size of the file name. If a name is 13 bytes (for 8.3 format), then a 2 KB block can hold up to 40 file descriptors. Blocks are connected to each other through a list.
Problems
When renaming files, so-called tree rebalancing may occur. Creating a file, renaming or erasing it may result in cascading directory blocks. In fact, a rename may fail due to lack of disk space, even if the file itself has not grown in size. To avoid this disaster, HPFS maintains a small pool of free blocks that can be used in the event of a disaster. This operation may require allocating additional blocks on a full disk. A pointer to this pool of free blocks is stored in SpareBlock.
Principles for placing files and directories on disk inHPFS:
· information about the location of files is dispersed throughout the disk, while records of each specific file located (if possible) in adjacent sectors and close to data on their location;
· directories are located in the middle of disk space;
· directories are stored as binary balanced tree with entries arranged in alphabetical order.
Reliability of data storage in HPFS
Any file system must have a means of correcting errors that occur when writing information to disk. The HPFS system uses for this emergency replacement mechanism ( hotfix).
If the HPFS file system encounters a problem while writing data to disk, it displays an error message. HPFS then stores the information that should have been written to the defective sector in one of the spare sectors reserved in advance for this eventuality. The list of free spare blocks is stored in the HPFS spare block. If an error is detected while writing data to a normal block, HPFS selects one of the free spare blocks and stores the data there. The file system then updates emergency replacement card in the reserve unit.
This map is simply pairs of double words, each of which is a 32-bit sector number.
The first number indicates the defective sector, and the second indicates the sector among the available spare sectors that was selected to replace it.
After replacing the defective sector with a spare one, the emergency replacement map is written to the disk, and a pop-up window appears on the screen informing the user that a disk write error has occurred. Every time the system writes or reads a disk sector, it looks at the recovery map and replaces all bad sector numbers with spare sector numbers with the corresponding data.
It should be noted that this number translation does not significantly affect system performance, since it is performed only when physically accessing the disk, and not when reading data from the disk cache.
File system NTFS
The NTFS (New Technology File System) file system contains a number of significant improvements and changes that significantly distinguish it from other file systems.
Note that with rare exceptions, with NTFS partitions can only be worked directly fromWindowsN.T. although there are corresponding implementations of file management systems for reading files from NTFS volumes for a number of OSes.
However, there are no full-fledged implementations for working with NTFS outside of Windows NT.
NTFS is not supported on the widely used Windows 98 and Windows Millennium Edition operating systems.
Key FeaturesNT FS
· work on large disks occurs efficiently (much more efficiently than in FAT);
· there are tools to restrict access to files and directories Þ NTFS partitions provide local security for both files and directories;
· a transaction mechanism has been introduced in which logging file operations Þ significant increase in reliability;
· many restrictions on the maximum number of disk sectors and/or clusters have been removed;
· a file name in NTFS, unlike the FAT and HPFS file systems, can contain any characters, including the full set of national alphabets, since the data is represented in Unicode - a 16-bit representation that gives 65535 different characters. The maximum length of a file name in NTFS is 255 characters.
· NTFS also has built-in compression capabilities that you can apply to individual files, entire directories, and even volumes (and subsequently undo or assign them as you wish).
Volume structure with the NTFS file system
An NTFS partition is called a volume (volume). Maximum possible sizes volumes (and file sizes) are 16 EB (exabyte 2**64).
Like other systems, NTFS divides a volume's disk space into clusters—blocks of data that are addressed as data units. NTFS supports cluster sizes from 512 bytes to 64 KB; the standard is a cluster of 2 or 4 KB in size.
All disk space in NTFS is divided into two unequal parts.
The first 12% of the disk is allocated to the so-called MFT zone - space that can be occupied by the main service metafile MFT.
It is not possible to write any data to this area. The MFT zone is always kept empty - this is done so that the MFT file, if possible, does not become fragmented as it grows.
The remaining 88% of the volume is regular file storage space.
MFT(masterfiletable - general file table) is essentially a directory of all other files on the disk, including itself. It is designed to determine the location of files.
MFT consists of fixed size records. The MFT record size (minimum 1 KB and maximum 4 KB) is determined when the volume is formatted.
Each entry corresponds to a file.
The first 16 entries are of a service nature and are not available to the operating system - they are called metafiles, and the very first metafile is the MFT itself.
These first 16 MFT elements are the only part of the disk that has a strictly fixed position. A copy of these same 16 entries is kept in the middle of the volume for reliability.
The remaining parts of the MFT file can be located, like any other file, in arbitrary locations on the disk.
Metafiles are of a service nature - each of them is responsible for some aspect of the system's operation. Metafiles are located in the root directory of the NTFS volume. They all begin with the name symbol "$", although it is difficult to obtain any information about them using standard means. In table The main metafiles and their purpose are given.
|
Metafile name |
Purpose of the metafile |
|
|
$MFT |
Master File Table itself |
|
|
$MFTmirr |
A copy of the first 16 MFT entries placed in the middle of the volume |
|
|
$LogFile |
Logging support file |
|
|
$Volume |
Service information - volume label, file system version, etc. |
|
|
$AttrDef |
List of standard file attributes on the volume |
|
|
Root directory |
||
|
$Bitmap |
Volume free space map |
|
|
$Boot |
Boot sector(if the partition is bootable) |
|
|
$Quota |
A file that records user rights to use disk space (this file only started working in Windows 2000 with NTFS 5.0) |
|
|
$Upcase |
File - a table of correspondence between uppercase and lowercase letters in file names. In NTFS, file names are written in Unicode (which amounts to 65 thousand different symbols) and looking for large and small equivalents in this case is a non-trivial task |
|
The corresponding MFT record stores all information about the file:
· file name,
· size;
· file attributes;
· position on the disk of individual fragments, etc.
If one MFT record is not enough for the information, then several records are used, and not necessarily consecutive ones.
If the file is not very large, then the file data is stored directly in the MFT, in the space remaining from the main data within one MFT record.
A file on an NTFS volume is identified by the so-called file link(File Reference), which is represented as a 64-bit number.
· file number that corresponds to the record number in MFT,
· and sequence numbers. This number is incremented whenever a given number in the MFT is reused, allowing the NTFS file system to perform internal integrity checks.
Each file in NTFS is represented by streams(streams), that is, it does not have “just data” as such, but there are streams.
One of the streams is the file data.
Most file attributes are also streams.
Thus, it turns out that the file has only one basic entity - the number in the MFT, and everything else, including its streams, is optional.
This approach can be used effectively - for example, you can “attach” another stream to a file by writing any data to it.
Standard attributes for files and directories on an NTFS volume have fixed names and type codes.
Catalog in NTFS is special file, which stores links to other files and directories.
The catalog file is divided into blocks, each containing
· file name,
basic attributes and
The root directory of the disk is no different from regular directories, except for a special link to it from the beginning of the MFT metafile.
The internal directory structure is a binary tree, similar to HPFS.
The number of files in the root and non-root directories is not limited.
The NTFS file system supports object model NT security: NTFS treats directories and files as different types of objects and maintains separate (albeit overlapping) lists of permissions for each type.
NTFS provides file-level security; this means that access rights to volumes, directories and files may depend on account user and the groups to which he belongs. Every time a user accesses a file system object, his access rights are checked against the permission list of that object. If the user has sufficient rights, his request is granted; otherwise the request is rejected. This security model applies both to local user registration on NT computers and to remote network requests.
The NTFS system also has certain self-healing capabilities. NTFS supports various mechanisms for verifying system integrity, including transaction logging, which allows file write operations to be replayed against a special system log.
At logging file operations, the file management system records the changes that occur in a special service file. At the beginning of an operation related to changing the file structure, a corresponding note is made. If any failure occurs during file operations, the said operation start mark remains indicated as incomplete. When you perform a file system integrity check after rebooting the machine, these pending operations will be canceled and the files will be restored to their original state. If the operation of changing data in files is completed normally, then in this very service logging support file the operation is marked as completed.
The main disadvantage of the file systemNTFS- service data takes up a lot of space (for example, each directory element takes up 2 KB) - for small partitions, service data can occupy up to 25% of the media volume.
Þ NTFS cannot be used to format floppy disks. You should not use it to format partitions smaller than 100 MB.
OS file system UNIX
In the UNIX world, there are several different types of file systems with their own external memory structure. The most well-known are the traditional UNIX System V (s5) file system and the UNIX BSD family file system (ufs).
Consider s 5.
A file on a UNIX system is a collection of random access characters.
The file has a structure that is imposed on it by the user.
The Unix file system is a hierarchical, multi-user file system.
The file system has a tree structure. The vertices (intermediate nodes) of the tree are directories with links to other directories or files. The leaves of the tree correspond to files or empty directories.
Comment. In fact, the Unix file system is not tree-based. The fact is that the system has the possibility of violating the hierarchy in the form of a tree, since it is possible to associate multiple names with the same file content.
Disk structure
The disk is divided into blocks. The data block size is determined when formatting the file system with the mkfs command and can be set to 512, 1024, 2048, 4096 or 8192 bytes.
We count 512 bytes (sector size).
Disk space is divided into the following areas (see figure):
· loading block;
· control superblock;
· array of i-nodes;
· area for storing the contents (data) of files;
· a set of free blocks (linked into a list);
|
Boot block |
|
Superblock |
|
i - node |
|
. . . |
|
i - node |
Comment. For the UFS file system - all this is repeated for a group of cylinders (except for the Boot block) + a special area is allocated to describe the group of cylinders
Boot block
The block is located in block #0. (Remember that placing this block in block zero system device determined by the hardware, since the hardware bootloader always accesses block zero of the system device. This is the last component of the file system that is hardware dependent.)
The boot block contains a promotion program that is used to initially launch the UNIX OS. In S 5 file systems, only the boot block of the root file system is actually used. In additional file systems, this area is present, but not used.
Superblock
It contains operational information about the state of the file system, as well as data about file system settings.
In particular, the superblock contains the following information
· number of i-nodes (index descriptors);
· partition size???;
· list of free blocks;
· list of free i-nodes;
· and other.
Let's pay attention! The free space on the disk is linked list of free blocks. This list is stored in a superblock.
List elements are arrays of 50 elements (if block = 512 bytes, then element = 16 bits):
· array elements No. 1-48 contain the numbers of free blocks of file block space from 2 to 49.
· element #0 contains a pointer to the continuation of the list, and
· the last element (No. 49) contains a pointer to a free element in the array.
If some process needs a free block to expand a file, then the system selects an array element using a pointer (to a free element), and the block with No. stored in this element is provided to the file. If the file is reduced, the freed numbers are added to the array of free blocks and the pointer to the free element is adjusted.
Since the array size is 50 elements, two critical situations are possible:
1. When we free blocks of files, but they cannot fit in this array. In this case, one free block is selected from the file system and the completely filled array of free blocks is copied into this block, after which the value of the pointer to the free element is reset, and the zero element of the array, which is located in the superblock, contains the number of the block that the system has chosen to copy the contents of the array. At this moment, a new element of the list of free blocks is created (each with 50 elements).
2. When the contents of the elements of the array of free blocks have been exhausted (in this case, the zero element of the array is zero). If this element is not equal to zero, then this means that there is a continuation of the array. This continuation is read into a copy of the superblock in RAM.
Free listi-nodes. This is a buffer consisting of 100 elements. It contains information about 100 numbers of i-nodes that are free at the moment.
The superblock is always in RAM
Þ all operations (releasing and occupying blocks and i-nodes occur in RAM Þ minimizing disk exchanges.
But! If the contents of the superblock are not written to the disk and the power is turned off, problems will arise (a discrepancy between the real state of the file system and the contents of the superblock). But this is already a requirement for the reliability of the system equipment.
Comment. UFS file systems support multiple copies of the superblock (one copy per cylinder group) to improve stability.
Inode Area
This is an array of file descriptions called i -nodes (i -node).(64 byte?)
Each index descriptor (i-node) of a file contains:
· File type (file/directory/special file/fifo/socket)
· Attributes (access rights) - 10
File owner ID
· Group ID of the file owner
· File creation time
File modification time
· Time of last access to the file
· File length
· Number of links to a given i-node from various directories
File block addresses
!note. There is no file name here
Let's take a closer look at how it is organized block addressing, in which the file is located. So, in the address field there are numbers of the first 10 blocks of the file.
If the file exceeds ten blocks, then the following mechanism begins to work: the 11th element of the field contains the block number, which contains 128 (256) links to blocks of this file. If the file is even larger, then the 12th element of the field is used - it contains the block number, which contains 128(256) block numbers, where each block contains 128(256) file system block numbers. And if the file is even larger, then the 13th element is used - where the nesting depth of the list is increased by another one.
This way we can get a file of size (10+128+128 2 +128 3)*512.
This can be represented as follows:
Address of the 1st block of the file
Address of the 2nd block of the file
Address of the 10th block of the file
Indirect addressing block address (block with 256 block addresses)
Address of the 2nd indirect addressing block (block with 256 address blocks with addresses)
Address of the 3rd indirect addressing block (block with addresses of blocks with addresses of blocks with addresses)
File protection
Now let's look at the owner and group IDs and security bits.
In Unix OS it is used three-level user hierarchy:
The first level is all users.
The second level is user groups. (All users are divided into groups.
The third level is a specific user (Groups consist of real users). Due to this three-level organization of users, each file has three attributes:
1) Owner of the file. This attribute is associated with one specific user, who is automatically assigned by the system as the owner of the file. You can become the default owner by creating a file, and there is also a command that allows you to change the owner of a file.
2) File access protection. Access to each file is limited to three categories:
· owner rights (what the owner can do with this file, in general case- not necessarily anything);
· rights of the group to which the file owner belongs. The owner is not included here (for example, a file can be read-locked for the owner, but all other group members can freely read from the file;
· all other users of the system;
For these three categories, three actions are regulated: reading from a file, writing to a file and executing a file (in the mnemonics of the R, W, X system, respectively). Each file in these three categories defines which user can read, which can write, and who can run it as a process.
Directory organization
From the OS point of view, a directory is a regular file that contains data about all the files that belong to the directory.
A directory element consists of two fields:
1)number of the i-node (ordinal number in the array of i-nodes) and
2)file name:
Each directory contains two special names: ‘.’ - the directory itself; ‘..’ - parent directory.
(For the root directory, the parent refers to the same directory.)
In general, a directory can contain multiple entries that refer to the same i-node, but the directory cannot contain entries with the same names. That is, an arbitrary number of names can be associated with the contents of the file. It is called tying. A directory entry that refers to a single file is called communication.
Files exist independently of directory entries, and directory links actually point to physical files. A file "disappears" when the last link pointing to it is deleted.
So, to access a file by name, operating system
1. finds this name in the directory containing the file,
2. gets the number of the i-node of the file,
3. by number finds the i-node in the area of i-nodes,
4. from the i-node receives the addresses of the blocks in which the file data is located,
5. reads blocks from the data area using block addresses.
Disk partition structure in EXT2 FS
The entire partition space is divided into blocks. A block can be 1, 2, or 4 kilobytes in size. A block is an addressable unit of disk space.
Blocks in their area are combined into groups of blocks. Groups of blocks in a file system and blocks within a group are numbered sequentially, starting with 1. The first block on the disk is numbered 1 and belongs to group number 1. Total number blocks on a disk (in a disk partition) is a divisor of disk space expressed in sectors. And the number of block groups does not have to divide the number of blocks, because the last block group may not be complete. The beginning of each group of blocks has an address, which can be obtained as ((group number - 1)* (number of blocks in the group)).
Each group of blocks has the same structure. Its structure is presented in the table.
The first element of this structure (superblock) is the same for all groups, and all the rest are individual for each group. The superblock is stored in the first block of each group of blocks (except for group 1, in which the first block contains boot record). Superblock is the starting point of the file system. It is 1024 bytes in size and is always located at offset 1024 bytes from the beginning of the file system. The presence of multiple copies of a superblock is explained by the extreme importance of this element of the file system. Superblock duplicates are used when recovering a file system after failures.
The information stored in the superblock is used to organize access to the rest of the data on the disk. The superblock determines the size of the file system, the maximum number of files in the partition, the amount of free space, and contains information about where to look for unallocated areas. When the OS starts, the superblock is read into memory and all changes to the file system are first reflected in a copy of the superblock located in the OS and are written to disk only periodically. This improves system performance because many users and processes are constantly updating files. On the other hand, when the system is turned off, the superblock must be written to disk, which does not allow turning off the computer by simply turning off the power. Otherwise, the next time you boot, the information recorded in the superblock will not correspond to the real state of the file system.
Following the superblock is a description of the group of blocks (Group Descriptors). This description contains:
Address of the block containing the block bitmap of this group;
Address of the block containing the inode bitmap of this group;
Address of the block containing the inode table of this group;
Counter of the number of free blocks in this group;
The number of free inodes in this group;
The number of inodes in a given group that are directories
and other data.
The information stored in the group description is used to locate the block and inode bitmaps, as well as the inode table.
File system Ext 2 is characterized by:
- hierarchical structure,
- coordinated processing of data sets,
- dynamic file extension,
- protection of information in files,
- treating peripheral devices (such as terminals and tape devices) as files.
Internal file representation
Each file in the Ext 2 system has a unique index. The index contains the information needed by any process to access the file. Processes access files using a well-defined set of system calls and identifying the file with a string of characters that acts as a qualified file name. Each compound name uniquely identifies a file, so the system kernel converts this name into a file index. The index includes a table of addresses where file information is located on disk. Since each block on a disk is addressed by its own number, this table stores a collection of disk block numbers. To increase flexibility, the kernel appends a file one block at a time, allowing the file's information to be scattered throughout the file system. But this layout complicates the task of searching for data. The address table contains a list of block numbers containing information belonging to the file.
File inodes
Each file on the disk has a corresponding file inode, which is identified by its serial number - the file index. This means that the number of files that can be created on a file system is limited by the number of inodes, which is either explicitly specified when the file system is created or calculated based on the physical size of the disk partition. Inodes exist on disk in static form and the kernel reads them into memory before working with them.
The file inode contains the following information:
|
- The type and access rights to this file. |
|
File owner identifier (Owner Uid). |
|
File size in bytes. |
|
Time of the last access to the file (Access time). |
|
File creation time. |
|
Time of the last modification of the file. |
|
File deletion time. |
|
Group ID (GID). |
|
Links count. |
|
The number of blocks occupied by the file. |
|
File flags |
|
Reserved for OS |
|
Pointers to blocks in which file data is written (an example of direct and indirect addressing in Fig. 1) |
|
File version (for NFS) |
|
ACL file |
|
Directory ACL |
|
Fragment address |
|
Fragment number |
|
Fragment size |
Catalogs
Directories are files.
The kernel stores data in a directory just as it does in a regular file type, using an index structure and blocks with direct and indirect addressing levels. Processes can read data from directories in the same way they read regular files However, exclusive write access to the directory is reserved by the kernel, ensuring that the directory structure is correct.)
When a process uses a file path, the kernel looks in the directories for the corresponding inode number. After the file name has been converted to an inode number, the inode is placed in memory and then used in subsequent requests.
Additional features of EXT2 FS
In addition to standard Unix features, EXT2fs provides some additional features not typically supported by Unix file systems.
File attributes allow you to change how the kernel reacts when working with sets of files. You can set attributes on a file or directory. In the second case, files created in this directory inherit these attributes.
During system mounting, some features related to file attributes may be set. The mount option allows the administrator to choose how files are created. In a BSD-specific file system, files are created with the same group ID as the parent directory. The features of System V are somewhat more complex. If a directory has its setgid bit set, then created files inherit the group ID of that directory, and subdirectories inherit the group ID and setgid bit. Otherwise, files and directories are created with the primary group ID of the calling process.
The EXT2fs system can use synchronous data modification similar to BSD system. The mount option allows the administrator to specify that all data (inodes, bit blocks, indirect blocks, and directory blocks) be written to disk synchronously when they are modified. This can be used to achieve high data recording capacity, but also results in poor performance. In reality, this function is not usually used because, in addition to degrading performance, it can lead to the loss of user data that is not flagged when checking the file system.
EXT2fs allows you to select the logical block size when creating a file system. It can be 1024, 2048 or 4096 bytes in size. Using larger blocks results in faster I/O operations (since fewer disk requests are made), and therefore less head movement. On the other hand, using large blocks leads to wasted disk space. Typically, the last block of a file is not completely used for storing information, so as the block size increases, the amount of wasted disk space increases.
EXT2fs allows you to use accelerated symbolic links. When using such links, file system data blocks are not used. The destination file name is not stored in the data block, but in the inode itself. This structure allows you to save disk space and speed up the processing of symbolic links. Of course, the space reserved for a handle is limited, so not every link can be represented as an accelerated link. The maximum length of a file name in an accelerated link is 60 characters. In the near future it is planned to expand this scheme for small files.
EXT2fs monitors the state of the file system. The kernel uses a separate field in the superblock to indicate the state of the file system. If the file system is mounted in read/write mode, then its state is set to "Not Clean". If it is dismantled or remounted in read-only mode, then its state is set to “Clean”. During system boot and file system status checks, this information is used to determine whether a file system check is necessary. The kernel also places some errors in this field. When the kernel detects a mismatch, the file system is marked as "Erroneous". The file system checker tests this information to check the system, even if its status is actually Clean.
Ignoring file system testing for a long time can sometimes lead to some difficulties, so EXT2fs includes two methods for regularly checking the system. The superblock contains the system mount counter. This counter is incremented each time the system is mounted in read/write mode. If its value reaches the maximum (it is also stored in the superblock), then the file system test program starts checking it, even if its state is "Clean". The last check time and the maximum interval between checks are also stored in the superblock. When the maximum interval between scans is reached, the state of the file system is ignored and its scan is started.
Performance optimization
The EXT2fs system contains many features that optimize its performance, which leads to increased speed of information exchange when reading and writing files.
EXT2fs actively uses the disk buffer. When a block needs to be read, the kernel issues an I/O operation request to several adjacent blocks. Thus, the kernel tries to make sure that the next block to be read has already been loaded into the disk buffer. Such operations are usually performed when reading files sequentially.
The EXT2fs system also contains a large number of optimizations for information placement. Block groups are used to group together corresponding inodes and data blocks. The kernel always tries to place the data blocks of one file in the same group, as well as its descriptor. This is intended to reduce the movement of the drive heads when reading the descriptor and its corresponding data blocks.
When writing data to a file, EXT2fs pre-allocates up to 8 contiguous blocks when allocating a new block. This method allows you to achieve high performance under heavy system load. This also allows files to be placed in contiguous blocks, which speeds up their subsequent reading.
Instructions
The file system defines the way data is organized and stored on various storage media, including hard drives. There are a large number of different file systems, the most common are: FAT16, FAT32, NTFS for operating systems of the Windows family; ext2 and ext3 for Unix systems and, in particular, for the operating system systems Linux.
Find out the file type systems possible in different ways. The simplest one: open “My Computer”, select the disk you are interested in, right-click it and select “Properties” from the menu. In the window that opens, the disk type and the file system used will be indicated at the top. For example, for Windows XP and Windows 7 the file type will be indicated systems NTFS.
If you have an inoperative computer that refuses to boot, you can view information about its disks using Acronis programs Dick Director. It runs directly from the CD, to select boot from the disk, press F12 after starting, a boot device selection window will appear in front of you. On some computers, the boot window may be called up using other keys.
Select boot from CD and press Enter. In the disk menu that appears, select Acronis Dick Director. After loading, a program window will open in which you will see all the computer’s disks and their partitions, indicating the file systems used. Acronis Dick Director is a very convenient utility that allows you to partition disks in the right way and format them in the required file system. It also allows you to restore disk partitions with a high degree of probability after their accidental loss - you can restore disks with all folders and files.
There is a version of the Acronis Dick Director program that runs under Windows, in which you can also view all information on file systems. But it is not recommended to perform any operations with disks in this version - after rebooting systems There is a fairly high risk that the computer will refuse to boot at all. If you need to partition your disk, use the CD version, it is very reliable.
Sources:
- How can I find out what file system I have?
From file hard systems The disk depends on many computer operating parameters. For example, if you are going to download large-capacity files (more than four gigabytes) from the Internet, then your hard drive must work under NTFS management. Also, the type of file system determines the speed of writing files to the hard drive and the speed of copying information from partition to partition.
You will need
- - PartitionMagic program;
- - TuneUp Utilities 2011 program.
Instructions
Using this method you can find out the file type systems regardless of your version of Windows. Open My Computer. Right-click on the hard drive partition. A context menu will appear. From this menu, select Properties. Next, look for the line “File system”. The file type will be written next to it. systems this partition of the hard drive.
Also find out the file type systems you can use the PartitionMagic program. This program is suitable both for owners of operating systems of the Windows family, and for those users who have an operating system installed Linux system. Find it on the Internet, download and install it on your computer’s hard drive.
Launch PartitionMagic. Wait a moment until the computer scanning process is completed. In the main program window you will see a list of all partitions on your hard drive. By going to the “Properties” section, you can view the file .
You can also use the TuneUp Utilities 2011 computer monitoring and configuration program to view information. It can be easily found on the Internet. Although the program is commercial, there is a trivial period of use. Download and install the application on your computer.
Launch TuneUp Utilities. Wait a while. When the program is launched for the first time, it begins scanning your computer. After scanning, you will be prompted to fix errors and optimize the system. If you have time, you can agree. Or cancel this procedure.
After this, you will find yourself in the main menu of the program. Select the “Troubleshooting” section, then in the next window - “Show system information”. After a few seconds, the “System Informer” window will appear. In this window, select the “Disks” section. In it you can find information about the file system.
When choosing software for your computer you need to know type, or its bit depth. In particular, the system can be 32 or 64 bit. These terms mainly refer to the way data is processed central processor. However, the software for 32-bit systems may be incompatible with 64-bit and vice versa. To know type systems can be found in the documentation. If documentation is missing, follow these steps:
You will need
- Computer running Windows operating system (XP, Vista, Windows 7) or Server 2003
Instructions
In order to determine systems in the Windows XP or Server 2003 operating system, open the "Properties" information window systems"(tab in the "System" application). It's in the Control Panel folder, in the Start menu (you can also open the Run dialog box from the Start menu, "sysdm.cpl" and press Enter).
In the application that opens, explore the “Properties” tab systems" If you have a 32 OS, you won't find any mention of this. But in 64-bit systems the bit depth is indicated. For example, the name of your systems may look like this: MS XP Professional x64.
If you want to make sure that you have defined type systems, open the Run window from the Start drop-down menu, type "winmsd.exe" and press Enter. On the right side of the application that opens next, find the line “Processor”. If the line before the name says "x86", you have a 32-bit OS. If the processor name begins with ia64 or AMD64, then your system is 64-bit.
If you have Vista or Windows7 installed, then to determine type systems on these operating systems, open and explore the “System” window, which is located in the “Control Panel” directory. Open the Start button menu. In "Start Search" write "system" and then click on "System" in the "Programs" list. In the window that opens, open “Type systems" If your OS has 32, you will see a corresponding inscription starting with the phrase “32-bit...”. Accordingly for 64- systems the inscription will begin with “64-bit...”.
Apart from this, you can also explore the System Information information window. To do this, open the Start menu and enter “system” into the search. Then click System Information under Programs. In the window that opens, find “Type systems" in the "Element" subsection. Here you can type systems according to the inscriptions: “x86-based” (32-bit OS) or “x64-based” (64-bit OS).
Video on the topic
Sources:
- how to change 64 in the system
When you work with a computer, you are always dealing with files. A file is a named volume of information. Information can be considered texts, media, and service data that the computer needs to operate.
To successfully process information, it needs to be systematized. This is what file systems do. Their purpose is to provide the ability to conveniently work with data and organize sharing files by multiple processes or users.
A person with computer experience will not store documents, movies and games in one folder, which is offered to him by default. It is more convenient to group data according to some criteria and place them in the appropriate sections. These sections are called directories.
From a file system point of view, a directory is a list that contains information about a group of files. This can be the name of the file, the name of its owner or creator, the physical address on the disk, the characteristics of “read-only”, “hidden”, “archive”, time of creation and modification, type (character, binary, temporary), etc.
One of the main tasks of the FS (file system) is the optimal placement of data on the disk. This means that disk space should be used economically, and searching and recording information should occur as quickly as possible.
The FS is written to the hard drive partition during formatting. One hard drive can contain several file systems. The choice of FS depends on which operating system will be installed on the logical disk.
For OS Windows, NTFS and, less commonly, FAT32 are used.
A logical drive larger than 32 GB cannot be formatted in FAT322 - a limitation imposed by Microsoft developers. In addition, this system can work with files no larger than 4 GB.
There is another significant drawback: FAT32 does not log, i.e. recording data operations and system state changes.
On the other hand, the advantage of FAT32 is its relatively high performance and low hardware requirements: it only needs 32 MB of RAM for normal operation.
The size of the logical disk that can be formatted in NTFS is 2,000,000 GB. This file system is characterized by stable operation due to journaling and information processing methods. All operations with data are carried out by a transaction, i.e. the action either completes correctly or is cancelled. Failures are recorded in the event log, from where the system takes information for self-healing.
The disadvantage of NTFS is the fragmentation of the hard drive. The built-in defragmentation program practically does not solve the problem due to the peculiarities of recording information on the hard drive.
In the process of improvement computer technology store at different times information accounted for on different media. The modern market is dominated by so-called hard drives. Sometimes it becomes necessary to find out the brand of the hard drive connected to your computer, the nominal capacity, free space, and so on.
You will need
- A computer with MS Windows OS, administrator rights for your user account, connected and correctly installed disks or other removable media.
Instructions
Go to "My Computer". Click on the "Local Disk (C:)" icon and right-click. In the context menu that opens, select "Properties". The local disk properties window will open, containing the most basic information about its status, including free space, nominal size, file system type, and others. You can also clean up the disk using MS Windows to increase free space.
In the local disk properties window, click on the "Hardware" tab. You will see a list of available disk devices of your computer, including the hard drive, CD-DVD ROM drives, virtual drives, and floppy drives, with the hard drive listed first. Having selected it with a mouse click, click on the "Properties" button. The properties window will open physical disk where you can find general information about it, define the data caching policy, and also see which driver controls its operation.
note
When a free space approaches on any of the local disks At a minimum, disk cleanup starts spontaneously. This is not dangerous, but it is better to avoid such a situation.
Helpful advice
You can get to the hard drive properties from the properties of other drives; to do this, just go to the “Hardware” tab. In addition, in order to avoid destabilization of the system, sometimes the disk needs to be scanned for errors and defragmented, so do not bypass the "Service" tab.
Each type of hard drive file system is unique in its own way. The most popular types NTFS and FAT32 have a number of differences. Sometimes you need a specific file system for a hard drive partition.
You will need
- Partition Manager, Windows disk.
Instructions
Insert the Windows installation disc and start your computer. Press Del to enter BIOS. Open the Boot Device Priority menu and assign your drive as a priority device. Select Save & Exit.
Run the operating system installer. Wait until the installation process reaches the partition selection menu. This is where the fun begins. If you are installing Windows XP, then select the partition on which the OS will be installed and in the next window set the “Format to type” option, where the word type means the file system type.
If you are dealing with a Windows Vista or Seven installer, then click the “Disk Setup” button. Select the partition whose file system type you want to change and click the Delete button. Now click the “Create” button, then specify the size of the future local disk and the type of its file system.
Now let's look at changing the partition file system without resorting to Windows. Download and install Partition program Manager. In the main menu of the program, select “Launch Partition Manager”. At the top you will see a list of sections hard drives. Right-click on the partition for which you want to change the filename system.
Select "Convert file" system" Specify the cluster size and type of future file system. Click the "Convert" button.
Video on the topic
Sources:
- how to change disk file system to ntfs
Tip 7: How to recover files after formatting a flash drive
If you accidentally formatted external USB drive, then try to return what is important to you files. For such cases, they were developed special programs, performing the process of searching for deleted data.
You will need
- - Easy Recovery.
Instructions
Please note that under no circumstances should you write any information to this USB drive. The more intensively you use after formatting, the less chance you have of restoring the necessary files. Download and install the Easy Recovery application. For this purpose, use the system partition of the hard drive.
Connect the formatted USB drive to the appropriate port on your computer or . Launch the Easy Recovery program. On the menu quick launch indicate the item Data Recovery. In the window that opens, select the Format Recovery menu. In the left window of the program, select the desired USB drive. Be sure to indicate previous type file system of this . Click Next.
Wait a while while the utility collects information about files previously stored on this USB drive. This process can take quite a long time. Much depends on the performance of your computer and the speed of the flash drive you are using. Wait for the new menu to appear.
Now check the boxes files that need to be restored. If you want to return all available information, then simply select the topmost folder in the left menu. Click Next. Specify the hard drive partition and folder into which deleted files will be restored files. Click Next again and wait for the information recovery process to complete.
If you need to restore documents of a certain type, then in the Quick Launch panel, select the File Repair menu. Select the document type from the menu that opens. These can be text documents, tables, and documents created using programs included with Microsoft Office. Follow a similar algorithm to find and recover lost data.
note
Data recovery after hard formatting disk. If data is lost, many people want to perform hdd recovery or flash drive recovery. To learn how to convert the file system of a flash drive from FAT to NTFS, read the article - how to format a flash drive to NTFS. Later I will write an article on how to restore deleted files using a powerful free program. so as not to miss.
Helpful advice
The R-Studio program is perfect for recovering data from a flash drive - DOWNLOAD. After launching the program, we immediately see a list of your storage devices. Select your flash drive and click on the “scan” button to start searching for lost files. Recovering data from a flash drive. And finally, here are the deleted files that the program was able to find on the flash drive. The found data will be presented in folders by file type, you will only have to select the desired file, deleted during formatting or...
