Hard disk partitioning is essentially a formatting of the hard disk, and then the hard disk can be used to save various information.
When creating a partition, the physical parameters of the hard disk have been set and the hard disk master boot record (Master Boot Record, generally referred to as MBR) has been specified. ) and the location where the boot record backup is stored. (Recommended learning: PHP Video Tutorial)
The information required for the file system and other operating systems to manage the hard disk is achieved through the subsequent advanced formatting, that is, the Format command.
In fact, you can create just one partition to use all or part of the hard disk space. However, no matter how many partitions are divided, or whether a SCSI hard disk or an IDE hard disk is used, the primary partition of the hard disk must be set as the active partition before the system can be started through the hard disk.
Disk partitioning is to use the partition editor to divide the disk into several logical parts. Once the disk is divided into several partitions, different types of directories and files can be stored in different partitions.
The more partitions there are, the more different places there are. The nature of the files can be distinguished more finely, and the files can be stored in different places to manage the files according to the more subdivided nature; but there are too many partitions. It became trouble.
The methods of space management, access permission and directory search depend on the file system installed on the partition. Partition size needs to be carefully considered when the ability to change the size depends on the file system mounted on the partition.
Disk partitioning can be seen as a simple technology that is the predecessor of logical volume management.
After the hard disk is partitioned, three forms of partition status will be formed: primary partition, extended partition and non-DOS partition.
Non-DOS Partition
Non-DOS Partition (Non-DOS Partition) is a special partition form in the hard disk. An area is divided separately for use by another operating system. For the operating system of the primary partition, it is a divided storage space. Only non-DOS partition operating systems can manage and use this storage area.
Primary partition
The primary partition is a relatively simple partition, usually located in the front area of the hard disk, forming a logical C disk. The main boot program is part of it. This program is mainly used to detect the correctness of the hard disk partition, determine the active partition, and transfer the boot right to DOS or other operating systems of the active partition. If this program is damaged, it will not be able to boot from the hard disk, but the hard disk can be read and written after booting from the floppy drive or optical drive.
Extended partition
The concept of extended partition is relatively complex, and it is very easy to cause confusion between hard disk partition and logical disk; the fourth byte of the partition table is the partition The type value is 06 for a normal bootable basic DOS partition larger than 32mb, and 05 for an extended DOS partition. If you change the basic DOS partition type to 05, the system cannot be started, and the data in it cannot be read or written.
If you change 06 to a type that is not recognized by DOS, such as efh, DOS will think that the partition is not a DOS partition, and of course it cannot read or write. Many people use this type of value to implement encryption technology for a single partition. Restoring the original correct type value can restore the partition to normal.
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