GUID partition table (GPT) was first introduced as a part of the Extensible Firmware Interface (EFI) initiative. GPT provides a more flexible mechanism for partitioning disks than the older Master Boot Record (MBR) partitioning scheme.

Why we need GPT?

GPT came into picture because of the limitations of MBR (Master Boot Record), which uses 32 bit for storing logical block addresses and size information. Due to which it only supports four partitions for a disk, allowing volume size less than 2.2TB.

GPT on the other hand, allocates 64 bits for logical block addresses and therefore allows a maximum disk and partition size of 9.4 ZB.

Few main benefits of the GPT are:

  • The size of the partition could be much higher as explained earlier.
  • Allows up to 128 primary partitions, instead of MBR which supports only 4 primary partitions.
  • Can be used as a storage volume on all x64 based systems.
  • MBR provides a 1-byte partition type code, which leads to many collisions, whereas GPT uses a 16-byte GUID (Globally Unique Identifier) value to identify partition types.
  • Stores a backup header and partition table at the end of the disk that aids in recovery in case the primary ones are damaged.

OS supported by GPT:

Maximum of all the modern OS’s support GPT and will work good, including Linux, Mac OSX, FreeBSD etc.
There is a detailed tutorial from Intel how to configure and install it in different OS’s, which is given in the References section.


  1. Wikipedia
  2. Intel
  3. Wiki ArcLinux
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