GUID Partition Table

Tags

comp-arch

Is an alternative partition record scheme to MBR supporting more partitions and partition sizes larger than 2 TiB. It also uses LBA.

GPT uses 64 bits for logical block addresses, allowing a maximum disk size of \( 2^{64} \)-sectors. For disks with 512-byte sectors the maximum size is 8 ZiB.

Protective MBR

In the interest of backward compatibility the space of the legacy MBR is still reserved in the GPT specification, however now it's only used to prevent MBR based utilities from recognising or possibly overwriting GPT disks.