Advanced and low-level formatting, low-level formatting

Advanced and low-level formatting, low-level formatting
Concept:

Formatting refers to the initialization of partitions in a disk or disk. This operation usually causes all files in an existing disk or partition to be cleared. Formatting is usually divided into low-level formatting and advanced formatting. If not specified, disk formatting usually refers to advanced formatting, while disk formatting usually includes both.

Formatting method:

Simply put, formatting initializes the disk so that we can record data on the disk step by step. For example, we have a big house to store books. Instead of moving books into the house, we need to set up bookshelves, Mark classes, and place books in different categories. Before using a new disk, you need to write some magnetic marks to each sector of the disk, you can use the data on the disk under the Operating System. This action is called formatting.

Format category:

Advanced and low-level formatting:

Formatting can be divided into high-level format and low-level format. The floppy disk only supports low-level formatting (although it looks like a high-level formatting). The Hard Disk not only supports advanced formatting, but also supports low-level formatting. Low-level formatting is based on hardware channels. This formatting operation is performed before hard disk partitioning and advanced formatting. Generally, users do not perform this operation.

If not specified, the common formatting actions refer to advanced formatting. In the MS-DOS operating system, we can use the FORMAT command to FORMAT the disk and floppy disk, for example, to format a disk in disk drive A: And put the boot file into the disk, use the 'format A:/s' command. in Windows, the formatting action is executed by 'Resource manager' (right-click the disk name --> "format ......").

The formatting action is usually to write the boot sector data at the beginning of the disk, record the disk label (volume label) in the root directory, and reserve some space for the File Allocation Table (FAT, and check whether any damaged sector exists on the disk. If yes, it indicates a damaged mark on the file allocation table (generally, the uppercase letter "B" indicates "BAD "), it indicates that data is not stored in this sector.

The difference between advanced formatting and low-level formatting:

Low-level formatting refers to dividing a blank disk into a cylindrical and track, and then dividing the track into several sectors. Each sector is also divided into the ID of the identification part, the GAP between partitions, and the DATA area. It can be seen that low-level formatting is a task before advanced formatting. It can only be completed in the DOS environment. In addition, low-level formatting can only target one hard disk, but cannot support a single partition. Low-level formatting has been performed by the hard disk manufacturer when each hard disk is released. Therefore, users do not need to perform low-level formatting. In fact, the full formatting of a floppy disk is a low-level formatting.

It should be noted that low-level formatting is a type of consumable operation, which has a negative impact on the hard disk life. Therefore, many hard drive manufacturers recommend that you do not have to do anything. When a hard disk is affected by an external strong magnetic body or a strong magnetic field, or due to long-term use, the disk is missing from the disk segment in the format of low-level formatting, resulting in a large number of "Bad Sectors, you can use low-level formatting to re-divide the "slice ". However, the premise is that the disk is not physically scratched.

Advanced formatting is used to clear data on the hard disk, generate boot zone information, initialize the FAT table, and label logical Bad Sectors. Generally, we reload the system with advanced formatting. Because MBR is not overwritten, there is a possibility of virus. MBR virus can be cleared through anti-virus software or fdisk/mbr rewrite MBR in DOS to completely clear the virus.