HP Pro 3420 GPT Hard Disk Drives for HP Business Desktops - Page 3

on the following shows a comparison of the MBR and GPT layouts., Protective MBR

Page 3 highlights

Primary GPT Protects MBR-based disk utilities from overwriting GPT drives Defines usable blocks on the disk List of drive partition entries (up to 128) Drive partitions (up to 128) LBA 0 LBA 1 LBA 2 LBA 3 Protective MBR Primary GPT Header Entries 1 thru 4 Entries 5 - 128 LBA 34 Partition 1 Partition 2 Remaining Partitions Secondary GPT Secondary/backup GPT header and partition entries LBA -34 LBA -33 LBA -2 LBA -1 NOTE: LBA -34 refers to the 34th addressable block address counted backwards from the last LBA on the drive. Entries 1 thru 4 Entries 5 - 128 Secondary GPT Header LBA = 512 bytes Figure 1. GPT partition table scheme Figure 2 on the following page shows a comparison of the MBR and GPT layouts. 3

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Figure 1. GPT partition table scheme
Figure 2 on the following page shows a comparison of the MBR and GPT layouts.
Protective MBR
Primary GPT Header
Entries 1 thru 4
Entries 5 – 128
Partition 1
Partition 2
Remaining Partitions
Entries 1 thru 4
Entries 5 – 128
Secondary GPT Header
Protects MBR-based
disk utilities
from overwriting
GPT drives
Defines usable
blocks on the disk
List of drive
partition entries
(up to 128)
Drive partitions
(up to 128)
Secondary/backup
GPT header and
partition entries
LBA = 512 bytes
NOTE: LBA -34 refers to the 34
th
addressable block
address counted backwards from the last LBA on
the drive.
Primary GPT
Secondary GPT
LBA 0
LBA 1
LBA 2
LBA 3
LBA -34
LBA 34
LBA -33
LBA -2
LBA -1