Changes

GPT disks differ quite considerably from MBR disks. In terms of capability, GPT supports disks up to 18 Exabytes in size with up 128 partitions. GPT also differs from MBR in terms of layout.

At the start of a GPT disk is an MBR. The MBR in this case, however, is provided purely so that the disk will be recognized by disk utilities that do not recognize GPT disks. To an MBR disk utility, the disk will appear to be an MBR disk with a single partition taking up the entire disk space.