Protects MBR-based

 

disk utilities

LBA 0

from overwriting

LBA 1

GPT drives

Defines usable

LBA 2

LBA 3

blocks on the disk

 

Protective MBR

Primary GPT Header

Entries 1 thru 4

Entries 5 – 128

Primary

List of drive partition entries (up to 128)

Drive partitions (up to 128)

LBA 34

LBA -34 LBA -33

Partition 1

Partition 2

Remaining Partitions

Entries 1 thru 4

Entries 5 – 128

GPT

Secondary/backup

GPT header and

partition entries

LBA -2

LBA -1

NOTE: LBA -34 refers to the 34th addressable block address counted backwards from the last LBA on the drive.

Secondary GPT Header

LBA = 512 bytes

GPT Secondary

Figure 1. GPT partition table scheme

Figure 2 on the following page shows a comparison of the MBR and GPT layouts.

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