Introduction:
A globally unique identifier partition table (GUID Partition Table, abbreviation: GPT) is a standard layout structure of a physical hard disk partition table. It is part of the Extensible Firmware Interface (UEFI) standard (Inter was used in place of the personal computer BIOS) in, (MBR) partition table is used instead of stored logical block address and size information of the recording master of a system BIOS of 32bits . For those sectors 512 bytes of disk, MBR partition does not support capacities greater than 2.2TB partition, however, some hard disk manufacturers aware of this limitation, and to upgrade their larger capacity disk to 4KB sectors, which MBR mean effective size limit raised to 16TiB. This seemingly "correct" solution temporarily reduces demand for improved disk allocation table, but also bring about in larger blocks (to the market block when booting from BIOS device) on how best to division disk partition confusion. GPT 64bits assigned to the logical block address, thereby making the maximum partition size of 2 64 -1 sectors becomes possible. For each sector size of 512 bytes of the disk, which means that there may be 9.4 ZB (9.4 × 10 21 is byte), or. 8 ZiB 512-byte (or bytes 9,444,732,965,739,290,426,880 18,446,744,073,709,551,615 (2 64 -1) sectors 512 × (2 . 9 ) bytes per sector).
Features:
MBR in the hard disk partition information directly stored in the master boot record (MBR) (for the master boot record further stores a boot program of the system). However, GPT hard disk, the location information stored in the partition table of GPT header. However, for compatibility reasons, the first sector of the hard disk is still used as the MBR, GPT is after the head.
Like with modern MBR, GPT also uses logical block address (LBA) replaced the earlier CHS addressing. Traditional MBR information is stored in LBA 0, GPT header is stored in LBA 1, the following table is the partition itself. 64-bit Windows operating system using 16,384 bytes (or 32 sectors) as GPT partition table, the next LBA 34 is a first partition of the hard disk starts.
To reduce the risk of damage to the partition table, GPT hard disk to save a copy of the final partition table.
