GUID: globally unique identifier
What is a GPT disk and how to create a GPT disk?GPT is the abbreviation of GUID Partition Table. The widespread MBR partitioning scheme, dating from the early 1980s, imposed limitations which affected the use of newer hardware. Intel therefore developed a new partition-table format in the late 1990s as part of what eventually became UEFI. The GPT as of 2010 forms a subset of the UEFI specification.
GPT vs. MBRCompared with MBR disk, A GPT disk can support larger than 2 TB volumes where MBR cannot. A GPT disk can be basic or dynamic, just like an MBR disk can be basic or dynamic. GPT disks also support up to 128 partitions rather than the 4 primary partitions limited to MBR. Also, GPT keeps a backup of the partition table at the end of the disk. Furthermore, GPT disk provides greater reliability due to replication and cyclical redundancy check (CRC) protection of the partition table. It can be used as a storage volume on all x64-based platforms, including platforms running Microsoft Windows XP Professional x64 Edition. Windows Server 2003 SP1 also enables support for GPT in x86 versions of the Windows Server 2003 family.
Disadvantages of MBR disk
Why we need GPT disk?
Solution 1: Convert MBR disk to GPT disk with EASEUS Partition Master
Solution 2: Convert MBR disk to GPT disk with Windows Disk Management
Solution 3: Convert MBR disk to GPT disk with Diskpart command------------------------------------------------
MBR is the standard partitioning scheme that's been used on hard disks since the PC first came out. It supports 4 primary partitions per hard drive, and a maximum partition size of 2TB.
GPT disks are new, and are readable only by Windows Server 2003 SP1, Windows Vista (all versions), and Windows XP x64 Edition. The GPT disk itself can support a volume up to 2^64 blocks in length. (For 512-byte blocks, this is 9.44 ZB - zettabytes. 1 ZB is 1 billion terabytes). It can also support theoretically unlimited partitions.
Windows restricts these limits further to 256 TB for a single partition (NTFS limit), and 128 partitions.
Only Itanium systems running Windows Server 2003 and Windows Vista systems with an EFI BIOS can boot from a GPT disk. The other operating systems mentioned earlier can use GPT disks as data disks but not boot disks.
For more information on GPT, see Problems with larger than 2TB arrays in the General Storage forum, and see Windows and GPT FAQ for additional information.
[...] is GPT which WinXP 32 cant read, so if you have sensible data on it copy it elsewhere and use Paul Gu|blog � Blog Archive � How to delete GPT Protective Partition to get the normal older MBR on it or get Vista or WinXP 64bit to be able to read a GPT disk. [...]
To get rid of the GPT Protective Partition without loosing data.