Hard drive formatting formats. Disk formatting

What is the procedure for formatting a disk? High-level and low-level formatting. Is it possible to recover data after the drive has been formatted?

Formatting refers to the process of marking storage media, which can be hard drives, optical media, devices using flash memory technologies, etc. Formatting can be carried out in various ways.

This process consists in forming a structure for accessing information located on a disk or device, for example, file structure. During this process, all information that was on the media is destroyed. Formatting may also include checking the integrity of the media.

Low-level formatting

This operation is characterized by the fact that special servo marks are applied to the surface of the disk. Such service marks allow you to position the heads hard drive. This formatting is done using a servowriter and is carried out during production hard drives in factory conditions.

Low-level formatting is sometimes called "real" formatting because the changes that occur in this process are physical in nature. A format is being created that will subsequently determine the positions of sectors and tracks. In the process of such formatting, service information is also applied, which will then be used by the servo system.

Low-level formatting is triggered when hard plates the disk does not contain any information. After this process, the plates will never be empty again, and the printed information will never be subject to changes.

High-level formatting

This formatting process creates a master boot record. It includes a table of partitions as well as structures file system, which is still empty. At the same time, the boot sector is installed, the condition of the media is checked, and defective sectors are discarded. There are also “quick” high-level formatting, which does not include checking the media.

After low-level formatting of a disk is completed, sectors and tracks are mapped onto it, but their contents are not systematized and are random. During high-level formatting, the file system structure is written to the disk, which later allows you to store data and programs on it.

This process is performed after the disk is divided into sections (partitions), this is done even if the drive is supposed to have only one partition that makes up its entire volume.

Formatting the hard drive in operating systems is currently performed either in installed system, or during its installation.

It should be understood that the difference between low-level and high-level formatting is quite significant. If there is a need to erase all information from a hard drive, high-level formatting can handle this task. However, you need to keep in mind that the files themselves are not affected in this case - information about where exactly they are located is erased. After such formatting, the disk will, in fact, be free of files and it will be possible to use its entire capacity. However modern technologies If necessary, they allow you to restore those files that were originally on the disk - however, only if they were not fragmented before formatting.

What should you do if you need to completely erase files without the possibility of further recovery? For this purpose they use special utilities, which perform the so-called zeroing - writing zeros over the entire surface of the disk. After this procedure, the disk can be formatted again to high level, but the data from it will no longer be recoverable.

The word formatting itself already formulates the answer to your question. Formatting is bringing something into a specific format. You can format not only disks, but also texts, floppy disks, optical media (CD/DVD/Blu-ray disks), solid-state drives (flash memory, SSD) and so on.

Why do you need to format disks?

This point can be explained in accessible language: HDD without formatting it looks like a crumpled piece of paper. When a disk is formatted, a sheet of paper is a smooth, flat surface on which information can be easily and simply written. How is formatting different from disk defragmentation? Formatting destroys data. Defragmentation does not destroy. That's the difference for you. When formatting a disk, all information is destroyed without a trace.

Text formatting

Bringing text to a specific format. That's what it means. Be sure to set a specific font (bold, italic, underlined). Select the font theme and font size. When formatting text, we can use text color and others available functions. In other words, we simply draw up the document. Formatted text is stored in text files, in the computer itself.

Three formatting processes

1. Low-level formatting (this is the basic markup of the data storage layer);
2. Splitting into stages (the volume of the hard drive is divided into logical drives C and D);
3. High-level formatting (this process forms logical structures).

Now you know what formatting is. We hope that our article was useful to you.

The process of marking a data storage area electronic storage media, located on the magnetic surface ( hard disks , floppy disks), optical media (CD/DVD/Blu-ray-disks), solid state drives ( flash memory - flash module, SSD) etc. There are different ways this process.

Formatting itself consists of creating (forming) data access structures, for example, structures file system. In this case, the possibility of direct access to the information located (which was located before formatting) on ​​the storage medium is lost, part of it is irretrievably destroyed. Some software utilities make it possible to restore some part (usually a large part) of information from formatted media. The formatting process can also check and correct the integrity of the media.

Formatting process

Formatting a hard drive involves three steps:

1. . This is a basic storage area layout that is performed at the factory as one of the final steps in manufacturing a storage device. In this process, physical structures are created in the data storage area: tracks - tracks(tracks), sectors, if necessary, program is recorded control information. Subsequently, in the vast majority of cases, this markup remains unchanged throughout the life of the medium. Most software utilities that claim to have low-level formatting capabilities actually, at best, only overwrite control information.
2. Partitioning. This process splits the hard drive capacity into logical drives(For example, C:, D:…; sda 1, sda 2…; hda 1, hda 2...). This is done using the built-in services itself operating system or corresponding utilities third party manufacturers(cm. Programs for working with partitions); the partitioning method depends significantly on the type operating system. This step is fundamentally optional (if you skip it, the entire volume of the media will consist of one partition), but due to the very large volumes of modern hard drives (up to 8,000 GB), they are usually divided into logical partitions.
3. . This process writes (forms) the logical structures responsible for the correct storage of files (file tables), and also, in some cases, boot files for sections that have active status. This formatting can be divided into two types: quick and full. At quick formatting only the table is overwritten file system, when complete - first the physical surface of the media is verified (checked), if necessary, corrected bad sectors, that is, areas of the optical surface that have physical damage(they are marked as faulty, which prevents information from being written to them in the future), and only then the file system table is written.

Low-level formatting

Low-level formatting (English Low level format) - an operation during which the magnetic surface hard drive so-called servo tags- service information that is used for positioning heads disk. Performed during the manufacturing process of the hard drive, on special equipment called servowriter.

Low-level formatting is the process of putting information about a position tracks And sectors, as well as recording service information for the servo system. This process is sometimes called "true" formatting because it creates a physical format that determines how the data will be arranged. When the process of low-level formatting a hard drive is started for the first time, the hard drive platters are empty, that is, they contain absolutely no information about sectors, tracks, and so on. This is the last moment when the hard drive has completely empty platters. Information recorded during this process will never be rewritten again.

Old hard disks had the same number of sectors per track and did not have built-in controllers, so the low-level formatting was handled by the external hard drive controller, and the only information it needed was the number of tracks and the number of sectors per track. Using this information, the external controller could format the hard drive. Modern hard drives have complex internal structure, which includes changing the number of sectors per track when moving from external to internal tracks, as well as built-in servo information to control the head drive. Also, modern drives use the technology of “invisible” bad sectors; they can automatically mark damaged sectors as non-working, eliminating the subsequent possibility of writing information to them. Due to such a complex data structure, all modern hard drives undergo low-level formatting only once - at the factory. There is no way to perform true low-level formatting at home on any modern hard drive, be it IDE/ATA , SATA or SCSI Winchester. Moreover, this cannot be done even in a service center.

Older hard drives required repeated low-level formatting throughout their life due to the effects thermal expansion associated with the use of stepper motors in head drive, in which the movement of the heads was divided into a grid with a fixed pitch. Over time, the physical location of sectors and tracks in such drives shifted, which did not allow information to be read correctly using stepper motor in the magnetic head drive. The head moved to the desired position, according to the controller, while the position of the specified track had already shifted, which led to the appearance of bad sectors. This problem was solved by reformatting the drive at a low level, rewriting tracks and sectors using a new grid of head drive steps. In modern drives that use a voice coil in the head drive, the problem of thermal expansion has faded into the background, forcing only temperature recalibration of the operating parameters of the head drive.

The result of performing “low-level” formatting from BIOS May be:

• lack of result, that is, the hard drive completely ignores this procedure. Positioning will be completed, but no actions will be performed on the disks;
• writing zeros to all sectors, that is, simply erasing user information;
• problems with hard drives of older series that do not provide reliable protection from the user. Some old hard drives with a capacity of 40-80 GB can command 50h respond with an error, which may result in all sectors being marked as " bad"or vice versa, write some of the service tracks as zeros, which will lead to the drive being inoperable.

Information cannot be restored in any way after real low-level formatting.

High-level formatting

High level full formatting- a process that involves creating master boot record with partition table and/or structures are empty file system, installation boot sector and similar actions, the result of which is the ability to use the media in operating system for storing programs and data. The formatting process also checks the integrity of the media surface to correct (block) bad sectors. There is also a method without checking the media, which is called “quick formatting”.

If you use, for example, an operating system DOS team format does this job by recording the master boot record and file allocation table as such a structure. High-level formatting is performed after the process of partitioning the disk into partitions (logical drives), even if only one partition will be used, occupying the entire volume of the drive. In modern operating systems, the processes of partitioning and formatting a hard drive can be performed both during the installation of the operating system, and on an already installed system using the system itself or third-party utilities, using a graphical, intuitive interface.