What is the gpt format?

The operating environment of this tutorial: windows7 system and Dell G3 computer.

The globally unique identification partition table (GPT) refers to the globally unique identification disk partition table format. It is used to replace the Master Boot Record (MBR) partition table in the BIOS system, which stores 32-bit logical block address and size information.

In MBR hard disk, partition information is directly stored in the master boot record (MBR) (MBR also stores the boot program of the system). But in GPT hard disk, the location information of partition table is stored in GPT header. However, for compatibility reasons, the first sector of the hard disk is still used as MBR, followed by GPT header.

Like modern MBR, GPT also uses logical block address (LBA) instead of the early CHS addressing method. Traditional MBR information is stored in LBA 0, GPT header is stored in LBA 1, and then the partition table itself. The 64-bit Windows operating system uses 16384 bytes (or 32 sectors) as the GPT partition table, and the next LBA 34 is the beginning of the first partition on the hard disk.

Apple once warned: [3] "Don't assume that the block size of all devices is 5 12 bytes." Some modern storage devices, such as SSD, may use blocks of 1024 bytes, and some magneto-optical disks (MO) may use sectors of 2048 bytes (but magneto-optical disks are usually not partitioned). Some hard disk manufacturers are planning to produce 4096-byte hard disks, but by the beginning of 20 10, this new hard disk used firmware to disguise the operating system as a 5 12-byte sector. [4]

MAC computers using Intel architecture also use GPT.

In order to reduce the risk of partition table damage, GPT keeps a copy of the partition table at the end of the hard disk.