The layout of a disk with the GUID Partition Table. In this example, each logical block is 512 bytes in size and each entry has 128 bytes. The corresponding partition entries are assumed to be located in LBA 2–33. Negative LBA addresses indicate a position from the end of the volume, with −1 being the last addressable block.

The GUID Partition Table (GPT) is a standard for the layout of partition tables of a physical computer storage device, such as a hard disk drive or solid-state drive, using universally unique identifiers, which are also known as globally unique identifiers (GUIDs). Forming a part of the Unified Extensible Firmware Interface (UEFI) standard (Unified EFI Forum-proposed replacement for the PC BIOS), it is nevertheless also used for some BIOSs, because of the limitations of master boot record (MBR) partition tables, which use 32 bits for logical block addressing (LBA) of traditional 512-byte disk sectors.

All modern personal computer operating systems support GPT. Some, including macOS and Microsoft Windows on the x86 architecture, support booting from GPT partitions only on systems with EFI firmware, but FreeBSD and most Linux distributions can boot from GPT partitions on systems with either the BIOS or the EFI firmware interface.


Main articles: INT 13H and Enhanced BIOS

The Master Boot Record (MBR) partitioning scheme, widely used since the early 1980s, imposed limitations for use of modern hardware. The available size for block addresses and related information is limited to 32 bits. For hard disks with 512‑byte sectors, the MBR partition table entries allow a maximum size of 2 TiB (2³² × 512‑bytes) or 2.20 TB (2.20 × 10¹² bytes).[1]

In the late 1990s, Intel developed a new partition table format as part of what eventually became the Unified Extensible Firmware Interface (UEFI). The GUID Partition Table is specified in chapter 5 of the UEFI 2.8 specification.[2] GPT uses 64 bits for logical block addresses, allowing a maximum disk size of 264 sectors. For disks with 512‑byte sectors, the maximum size is 8 ZiB (264 × 512‑bytes) or 9.44 ZB (9.44 × 10²¹ bytes).[1] For disks with 4,096‑byte sectors the maximum size is 64 ZiB (264 × 4,096‑bytes) or 75.6 ZB (75.6 × 10²¹ bytes).

In 2010, hard-disk manufacturers introduced drives with 4,096‑byte sectors (Advanced Format).[3] For compatibility with legacy hardware and software, those drives include an emulation technology (512e) that presents 512‑byte sectors to the entity accessing the hard drive, despite their underlying 4,096‑byte physical sectors.[4] Performance could be degraded on write operations, when the drive is forced to perform two read-modify-write operations to satisfy a single misaligned 4,096‑byte write operation.[5] Since April 2014, enterprise-class drives without emulation technology (4K native) have been available on the market.[6][7]

Readiness of the support for 4 KB logical sectors within operating systems differs among their types, vendors and versions.[8] For example, Microsoft Windows supports 4K native drives since Windows 8 and Windows Server 2012 (both released in 2012) in UEFI.[9]


Like MBR, GPT uses logical block addressing (LBA) in place of the historical cylinder-head-sector (CHS) addressing. The protective MBR is stored at LBA 0, and the GPT header is in LBA 1, with a backup GPT header stored at the final LBA. The GPT header has a pointer to the partition table (Partition Entry Array), which is typically at LBA 2. Each entry on the partition table has a size of 128 bytes. The UEFI specification stipulates that a minimum of 16,384 bytes, regardless of sector size, are allocated for the Partition Entry Array.[10] Thus, on a disk with 512-byte sectors, at least 32 sectors are used for the Partition Entry Array, and the first usable block is at LBA 34 or higher, while on a 4,096-byte sectors disk, at least 4 sectors are used for the Partition Entry Array, and the first usable block is at LBA 6 or higher.

MBR variants

Protective MBR (LBA 0)

For limited backward compatibility, the space of the legacy Master Boot Record (MBR) is still reserved in the GPT specification, but it is now used in a way that prevents MBR-based disk utilities from misrecognizing and possibly overwriting GPT disks. This is referred to as a protective MBR.[11]

A single partition of type EEh, encompassing the entire GPT drive (where "entire" actually means as much of the drive as can be represented in an MBR), is indicated and identifies it as GPT. Operating systems and tools which cannot read GPT disks will generally recognize the disk as containing one partition of unknown type and no empty space, and will typically refuse to modify the disk unless the user explicitly requests and confirms the deletion of this partition. This minimizes accidental erasures.[11] Furthermore, GPT-aware OSes may check the protective MBR and if the enclosed partition type is not of type EEh or if there are multiple partitions defined on the target device, the OS may refuse to manipulate the partition table.[12]

If the actual size of the disk exceeds the maximum partition size representable using the legacy 32-bit LBA entries in the MBR partition table, the recorded size of this partition is clipped at the maximum, thereby ignoring the rest of the disk. This amounts to a maximum reported size of 2 TiB, assuming a disk with 512 bytes per sector (see 512e). It would result in 16 TiB with 4 KiB sectors (4Kn), but since many older operating systems and tools are hard coded for a sector size of 512 bytes or are limited to 32-bit calculations, exceeding the 2 TiB limit could cause compatibility problems.[11]

Hybrid MBR (LBA 0 + GPT)

In operating systems that support GPT-based boot through BIOS services rather than EFI, the first sector may also still be used to store the first stage of the bootloader code, but modified to recognize GPT partitions. The bootloader in the MBR must not assume a sector size of 512 bytes.[11]

Partition table header (LBA 1)

GPT header format
Offset Length Contents
0 (0x00) 8 bytes Signature ("EFI PART", 45h 46h 49h 20h 50h 41h 52h 54h or 0x5452415020494645ULL[a] on little-endian machines)
8 (0x08) 4 bytes Revision number of header - 1.0 (00h 00h 01h 00h) for UEFI 2.10
12 (0x0C) 4 bytes Header size in little endian (in bytes, usually 5Ch 00h 00h 00h or 92 bytes)
16 (0x10) 4 bytes CRC32 of header (offset +0 to +0x5b) in little endian, with this field zeroed during calculation
20 (0x14) 4 bytes Reserved; must be zero
24 (0x18) 8 bytes Current LBA (location of this header copy)
32 (0x20) 8 bytes Backup LBA (location of the other header copy)
40 (0x28) 8 bytes First usable LBA for partitions (primary partition table last LBA + 1)
48 (0x30) 8 bytes Last usable LBA (secondary partition table first LBA − 1)
56 (0x38) 16 bytes Disk GUID in mixed endian[12]
72 (0x48) 8 bytes Starting LBA of array of partition entries (usually 2 for compatibility)
80 (0x50) 4 bytes Number of partition entries in array
84 (0x54) 4 bytes Size of a single partition entry (usually 80h or 128)
88 (0x58) 4 bytes CRC32 of partition entries array in little endian
92 (0x5C) * Reserved; must be zeroes for the rest of the block (420 bytes for a sector size of 512 bytes; but can be more with larger sector sizes)

The partition table header defines the usable blocks on the disk. It also defines the number and size of the partition entries that make up the partition table (offsets 80 and 84 in the table).[2]: 119 

Partition entries (LBA 2–33)

GUID partition entry format
Offset Length Contents
0 (0x00) 16 bytes Partition type GUID (mixed endian[12])
16 (0x10) 16 bytes Unique partition GUID (mixed endian)
32 (0x20) 8 bytes First LBA (little endian)
40 (0x28) 8 bytes Last LBA (inclusive, usually odd)
48 (0x30) 8 bytes Attribute flags (e.g. bit 60 denotes read-only)
56 (0x38) 72 bytes Partition name (36 UTF-16LE code units)

After the primary header and before the backup header, the Partition Entry Array describes partitions, using a minimum size of 128 bytes for each entry block.[13] The starting location of the array on disk, and the size of each entry, are given in the GPT header. The first 16 bytes of each entry designate the partition type's globally unique identifier (GUID). For example, the GUID for an EFI system partition is C12A7328-F81F-11D2-BA4B-00A0C93EC93B. The second 16 bytes are a GUID unique to the partition. Then follow the starting and ending 64 bit LBAs, partition attributes, and the 36 character (max.) Unicode partition name. As is the nature and purpose of GUIDs and as per RFC 4122, no central registry is needed to ensure the uniqueness of the GUID partition type designators.[14][2]: 2200

The 64-bit partition table attributes are shared between 48-bit common attributes for all partition types, and 16-bit type-specific attributes:

Partition attributes
Bit Content
0 Platform required (required by the computer to function properly, OEM partition for example, disk partitioning utilities must preserve the partition as is)
1 EFI firmware should ignore the content of the partition and not try to read from it
2 Legacy BIOS bootable (equivalent to active flag (typically bit 7 set) at offset +0h in partition entries of the MBR partition table)[15]
3–47 Reserved for future use
48–63 Defined and used by the individual partition type

Microsoft defines the type-specific attributes for basic data partition as:[16][17]

Basic data partition attributes
Bit Content
60 Read-only
61 Shadow copy (of another partition)
62 Hidden
63 No drive letter (i.e. do not automount)

Google defines the type-specific attributes for ChromeOS kernel as:[18]

ChromeOS kernel partition attributes
Bit Content
56 Successful boot flag
55–52 Tries remaining
51–48 Priority (15: highest, 1: lowest, 0: not bootable)

Operating-system support

See also: UEFI: Disk device compatibility

UNIX and Unix-like systems

Details of GPT support on UNIX and Unix-like operating systems
OS family Version or edition Platform Read and write support Boot support Note
FreeBSD Since 7.0 IA-32, x86-64, ARM Yes Yes In a hybrid configuration, both GPT and MBR partition identifiers may be used.
Linux Most of the x86 Linux distributions
Fedora 8+ and Ubuntu 8.04+[19]
IA-32, x86-64, ARM Yes Yes Tools such as gdisk, GNU Parted,[20][21] util-linux v2.23+ fdisk,[22][23] SYSLINUX, GRUB 0.96 + patches and GRUB 2 have been GPT-enabled. Limited to 256 partitions per disk.[24]
macOS Since 10.4.0 (some features since 10.4.6)[25] IA-32, x86-64, PowerPC, Apple silicon Yes Yes Only Intel and Apple silicon Macintosh computers can boot from GPT.
MidnightBSD Since 0.4-CURRENT IA-32, x86-64 Yes Requires CSM In a hybrid configuration, both GPT and MBR partition identifiers may be used.
NetBSD Since 6.0[26] IA-32,[27] x86-64,[28] ARM Yes Yes
OpenBSD Since 5.9 IA-32, x86-64, ARM Yes Yes [29]
Solaris Since Solaris 10 IA-32, x86-64, SPARC Yes Yes [30]
HP-UX Since HP-UX 11.20 IA-64 Yes Yes [31]

Windows: 32-bit versions

Windows 7 and earlier do not support UEFI on 32-bit platforms, and therefore do not allow booting from GPT partitions.[32]

Details of GPT support on 32-bit editions of Microsoft Windows[32]
OS version Release date Platform Read or write support Boot support Note
Windows 9x 1995-08-24 IA-32 No[b] No
Windows XP 2001-10-25 IA-32 No No
Windows Server 2003 2003-04-24 IA-32 No No
Windows Server 2003 SP1 2005-03-30 IA-32 Yes No MBR takes precedence in hybrid configuration.
Windows Vista 2006-07-22 IA-32 Yes No MBR takes precedence in hybrid configuration.
Windows Server 2008 2008-02-27 IA-32 Yes No MBR takes precedence in hybrid configuration.
Windows 7 2009-10-22 IA-32 Yes No MBR takes precedence in hybrid configuration.
Windows 8 2012-08-01 IA-32 Yes Requires UEFI[33] MBR takes precedence in hybrid configuration.
Windows 8.1 2013-08-27 IA-32 Yes Requires UEFI[34] MBR takes precedence in hybrid configuration.
Windows 10 2015-07-29 IA-32 Yes Requires UEFI[35] MBR takes precedence in hybrid configuration.

Windows: 64-bit versions

Limited to 128 partitions per disk.[32]

Details of GPT support on 64-bit editions of Microsoft Windows[32]
OS version Release date Platform Read and write support Boot support Note
Windows XP 64-Bit Edition for Itanium systems, Version 2002 2001-10-25 IA-64 Yes Yes MBR takes precedence in hybrid configuration.
Windows XP 64-Bit Edition, Version 2003 2003-03-28 IA-64 Yes Yes MBR takes precedence in hybrid configuration.
Windows XP Professional x64 Edition
Windows Server 2003
2005-04-25[36] x64 Yes No MBR takes precedence in hybrid configuration.
Windows Server 2003 2005-04-25 IA-64 Yes Yes MBR takes precedence in hybrid configuration.
Windows Vista 2006-07-22 x64 Yes Requires UEFI[c] MBR takes precedence in hybrid configuration.
Windows Server 2008 2008-02-27 x64 Yes Requires UEFI MBR takes precedence in hybrid configuration.
Windows Server 2008 2008-02-27 IA-64 Yes Yes MBR takes precedence in hybrid configuration.
Windows 7 2009-10-22 x64 Yes Requires UEFI[d] MBR takes precedence in hybrid configuration.
Windows Server 2008 R2 2009-10-22 IA-64 Yes Yes MBR takes precedence in hybrid configuration.
Windows 8
Windows Server 2012
2012-08-01 x64 Yes Requires UEFI[37] MBR takes precedence in hybrid configuration.
Windows 8.1 2013-08-27 x64 Yes Requires UEFI[38] MBR takes precedence in hybrid configuration.
Windows 10 2015-07-29 x64 Yes Requires UEFI[39] MBR takes precedence in hybrid configuration.
Windows Server 2016 2016-10-12 x64 Yes Requires UEFI MBR takes precedence in hybrid configuration.
Windows Server 2019 2018-10-02 x64 Yes Requires UEFI MBR takes precedence in hybrid configuration.
Windows Server 2022 2021-08-18[40] x64 Yes Requires UEFI MBR takes precedence in hybrid configuration.
Windows 11 2021-10-05 x64, ARM64 Yes Yes UEFI is a system requirement for Windows 11.

Partition type GUIDs

"Partition type GUID" means that each partition type is strictly identified by a GUID number unique to that type, and therefore partitions of the same type will all have the same "partition type GUID". Each partition also has a "partition unique GUID" as a separate entry, which as the name implies is a unique id for each partition.

Operating system Partition type Globally unique identifier (GUID)[e]
Unused entry 00000000-0000-0000-0000-000000000000
MBR partition scheme 024DEE41-33E7-11D3-9D69-0008C781F39F
EFI System partition C12A7328-F81F-11D2-BA4B-00A0C93EC93B
BIOS boot partition[f] 21686148-6449-6E6F-744E-656564454649
Intel Fast Flash (iFFS) partition (for Intel Rapid Start technology)[41][42] D3BFE2DE-3DAF-11DF-BA40-E3A556D89593
Sony boot partition[g] F4019732-066E-4E12-8273-346C5641494F
Lenovo boot partition[g] BFBFAFE7-A34F-448A-9A5B-6213EB736C22
Windows Microsoft Reserved Partition (MSR)[44] E3C9E316-0B5C-4DB8-817D-F92DF00215AE
Basic data partition[44][h] EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
Logical Disk Manager (LDM) metadata partition[44] 5808C8AA-7E8F-42E0-85D2-E1E90434CFB3
Logical Disk Manager data partition[44] AF9B60A0-1431-4F62-BC68-3311714A69AD
Windows Recovery Environment[44] DE94BBA4-06D1-4D40-A16A-BFD50179D6AC
IBM General Parallel File System (GPFS) partition 37AFFC90-EF7D-4E96-91C3-2D7AE055B174
Storage Spaces partition[46] E75CAF8F-F680-4CEE-AFA3-B001E56EFC2D
Storage Replica partition[47] 558D43C5-A1AC-43C0-AAC8-D1472B2923D1
HP-UX Data partition 75894C1E-3AEB-11D3-B7C1-7B03A0000000
Service partition E2A1E728-32E3-11D6-A682-7B03A0000000
Linux[48][49][50][51] Linux filesystem data[h] 0FC63DAF-8483-4772-8E79-3D69D8477DE4
RAID partition A19D880F-05FC-4D3B-A006-743F0F84911E
Root partition (x86)[48][49] 44479540-F297-41B2-9AF7-D131D5F0458A
Root partition (x86-64)[48][49] 4F68BCE3-E8CD-4DB1-96E7-FBCAF984B709
Root partition (32-bit ARM)[48][49] 69DAD710-2CE4-4E3C-B16C-21A1D49ABED3
Root partition (64-bit ARM/AArch64)[48][49] B921B045-1DF0-41C3-AF44-4C6F280D3FAE
/boot partition[48][49] BC13C2FF-59E6-4262-A352-B275FD6F7172
Swap partition[48][49] 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F
Logical Volume Manager (LVM) partition E6D6D379-F507-44C2-A23C-238F2A3DF928
/home partition[48][49] 933AC7E1-2EB4-4F13-B844-0E14E2AEF915
/srv (server data) partition[48][49] 3B8F8425-20E0-4F3B-907F-1A25A76F98E8
Plain dm-crypt partition[52][53][54] 7FFEC5C9-2D00-49B7-8941-3EA10A5586B7
LUKS partition[52][53][54][55] CA7D7CCB-63ED-4C53-861C-1742536059CC
Reserved 8DA63339-0007-60C0-C436-083AC8230908
GNU/Hurd[56] Linux filesystem data[57] 0FC63DAF-8483-4772-8E79-3D69D8477DE4
Linux Swap partition[58] 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F
FreeBSD Boot partition[59] 83BD6B9D-7F41-11DC-BE0B-001560B84F0F
BSD disklabel partition[59] 516E7CB4-6ECF-11D6-8FF8-00022D09712B
Swap partition[59] 516E7CB5-6ECF-11D6-8FF8-00022D09712B
Unix File System (UFS) partition[59] 516E7CB6-6ECF-11D6-8FF8-00022D09712B
Vinum volume manager partition[59] 516E7CB8-6ECF-11D6-8FF8-00022D09712B
ZFS partition[59] 516E7CBA-6ECF-11D6-8FF8-00022D09712B
nandfs partition[60] 74BA7DD9-A689-11E1-BD04-00E081286ACF
Hierarchical File System Plus (HFS+) partition 48465300-0000-11AA-AA11-00306543ECAC
Apple APFS container
APFS FileVault volume container
Apple UFS container 55465300-0000-11AA-AA11-00306543ECAC
ZFS[i] 6A898CC3-1DD2-11B2-99A6-080020736631
Apple RAID partition 52414944-0000-11AA-AA11-00306543ECAC
Apple RAID partition, offline 52414944-5F4F-11AA-AA11-00306543ECAC
Apple Boot partition (Recovery HD) 426F6F74-0000-11AA-AA11-00306543ECAC
Apple Label 4C616265-6C00-11AA-AA11-00306543ECAC
Apple TV Recovery partition 5265636F-7665-11AA-AA11-00306543ECAC
Apple Core Storage Container
HFS+ FileVault volume container
Apple APFS Preboot partition 69646961-6700-11AA-AA11-00306543ECAC
Apple APFS Recovery partition 52637672-7900-11AA-AA11-00306543ECAC
Boot partition 6A82CB45-1DD2-11B2-99A6-080020736631
Root partition 6A85CF4D-1DD2-11B2-99A6-080020736631
Swap partition 6A87C46F-1DD2-11B2-99A6-080020736631
Backup partition 6A8B642B-1DD2-11B2-99A6-080020736631
/usr partition[i] 6A898CC3-1DD2-11B2-99A6-080020736631
/var partition 6A8EF2E9-1DD2-11B2-99A6-080020736631
/home partition 6A90BA39-1DD2-11B2-99A6-080020736631
Alternate sector 6A9283A5-1DD2-11B2-99A6-080020736631
Reserved partition 6A945A3B-1DD2-11B2-99A6-080020736631
NetBSD[61][j] Swap partition 49F48D32-B10E-11DC-B99B-0019D1879648
FFS partition 49F48D5A-B10E-11DC-B99B-0019D1879648
LFS partition 49F48D82-B10E-11DC-B99B-0019D1879648
RAID partition 49F48DAA-B10E-11DC-B99B-0019D1879648
Concatenated partition 2DB519C4-B10F-11DC-B99B-0019D1879648
Encrypted partition 2DB519EC-B10F-11DC-B99B-0019D1879648
ChromeOS[62] ChromeOS kernel FE3A2A5D-4F32-41A7-B725-ACCC3285A309
ChromeOS rootfs 3CB8E202-3B7E-47DD-8A3C-7FF2A13CFCEC
ChromeOS firmware CAB6E88E-ABF3-4102-A07A-D4BB9BE3C1D3
ChromeOS future use 2E0A753D-9E48-43B0-8337-B15192CB1B5E
ChromeOS miniOS 09845860-705F-4BB5-B16C-8A8A099CAF52
ChromeOS hibernate 3F0F8318-F146-4E6B-8222-C28C8F02E0D5
Container Linux by CoreOS[63] /usr partition (coreos-usr) 5DFBF5F4-2848-4BAC-AA5E-0D9A20B745A6
Resizable rootfs (coreos-resize) 3884DD41-8582-4404-B9A8-E9B84F2DF50E
OEM customizations (coreos-reserved) C95DC21A-DF0E-4340-8D7B-26CBFA9A03E0
Root filesystem on RAID (coreos-root-raid) BE9067B9-EA49-4F15-B4F6-F36F8C9E1818
Haiku[64] Haiku BFS 42465331-3BA3-10F1-802A-4861696B7521
MidnightBSD[65][j] Boot partition 85D5E45E-237C-11E1-B4B3-E89A8F7FC3A7
Data partition 85D5E45A-237C-11E1-B4B3-E89A8F7FC3A7
Swap partition 85D5E45B-237C-11E1-B4B3-E89A8F7FC3A7
Unix File System (UFS) partition 0394EF8B-237E-11E1-B4B3-E89A8F7FC3A7
Vinum volume manager partition 85D5E45C-237C-11E1-B4B3-E89A8F7FC3A7
ZFS partition 85D5E45D-237C-11E1-B4B3-E89A8F7FC3A7
Ceph[k] Journal 45B0969E-9B03-4F30-B4C6-B4B80CEFF106
dm-crypt journal 45B0969E-9B03-4F30-B4C6-5EC00CEFF106
OSD 4FBD7E29-9D25-41B8-AFD0-062C0CEFF05D
dm-crypt OSD 4FBD7E29-9D25-41B8-AFD0-5EC00CEFF05D
Disk in creation 89C57F98-2FE5-4DC0-89C1-F3AD0CEFF2BE
dm-crypt disk in creation 89C57F98-2FE5-4DC0-89C1-5EC00CEFF2BE
Block CAFECAFE-9B03-4F30-B4C6-B4B80CEFF106
Block DB 30CD0809-C2B2-499C-8879-2D6B78529876
Block write-ahead log 5CE17FCE-4087-4169-B7FF-056CC58473F9
Lockbox for dm-crypt keys FB3AABF9-D25F-47CC-BF5E-721D1816496B
Multipath OSD 4FBD7E29-8AE0-4982-BF9D-5A8D867AF560
Multipath journal 45B0969E-8AE0-4982-BF9D-5A8D867AF560
Multipath block CAFECAFE-8AE0-4982-BF9D-5A8D867AF560
Multipath block 7F4A666A-16F3-47A2-8445-152EF4D03F6C
Multipath block DB EC6D6385-E346-45DC-BE91-DA2A7C8B3261
Multipath block write-ahead log 01B41E1B-002A-453C-9F17-88793989FF8F
dm-crypt block CAFECAFE-9B03-4F30-B4C6-5EC00CEFF106
dm-crypt block DB 93B0052D-02D9-4D8A-A43B-33A3EE4DFBC3
dm-crypt block write-ahead log 306E8683-4FE2-4330-B7C0-00A917C16966
dm-crypt LUKS journal 45B0969E-9B03-4F30-B4C6-35865CEFF106
dm-crypt LUKS block CAFECAFE-9B03-4F30-B4C6-35865CEFF106
dm-crypt LUKS block DB 166418DA-C469-4022-ADF4-B30AFD37F176
dm-crypt LUKS block write-ahead log 86A32090-3647-40B9-BBBD-38D8C573AA86
dm-crypt LUKS OSD 4FBD7E29-9D25-41B8-AFD0-35865CEFF05D
OpenBSD Data partition 824CC7A0-36A8-11E3-890A-952519AD3F61
QNX Power-safe (QNX6) file system[68] CEF5A9AD-73BC-4601-89F3-CDEEEEE321A1
Plan 9 Plan 9 partition C91818F9-8025-47AF-89D2-F030D7000C2C
VMware ESX vmkcore (coredump partition) 9D275380-40AD-11DB-BF97-000C2911D1B8
VMFS filesystem partition AA31E02A-400F-11DB-9590-000C2911D1B8
VMware Reserved 9198EFFC-31C0-11DB-8F78-000C2911D1B8
Android-IA[69][70][71][72] Bootloader 2568845D-2332-4675-BC39-8FA5A4748D15
Bootloader2 114EAFFE-1552-4022-B26E-9B053604CF84
Boot 49A4D17F-93A3-45C1-A0DE-F50B2EBE2599
Recovery 4177C722-9E92-4AAB-8644-43502BFD5506
Misc EF32A33B-A409-486C-9141-9FFB711F6266
Metadata 20AC26BE-20B7-11E3-84C5-6CFDB94711E9
System 38F428E6-D326-425D-9140-6E0EA133647C
Cache A893EF21-E428-470A-9E55-0668FD91A2D9
Data DC76DDA9-5AC1-491C-AF42-A82591580C0D
Persistent EBC597D0-2053-4B15-8B64-E0AAC75F4DB1
Vendor C5A0AEEC-13EA-11E5-A1B1-001E67CA0C3C
Config BD59408B-4514-490D-BF12-9878D963F378
Factory 8F68CC74-C5E5-48DA-BE91-A0C8C15E9C80
Factory (alt)[73] 9FDAA6EF-4B3F-40D2-BA8D-BFF16BFB887B
Fastboot / Tertiary[74][75] 767941D0-2085-11E3-AD3B-6CFDB94711E9
OEM AC6D7924-EB71-4DF8-B48D-E267B27148FF
Android 6.0+ ARM Android Meta 19A710A2-B3CA-11E4-B026-10604B889DCF
Android EXT 193D1EA4-B3CA-11E4-B075-10604B889DCF
Open Network Install Environment (ONIE) Boot 7412F7D5-A156-4B13-81DC-867174929325
Config D4E6E2CD-4469-46F3-B5CB-1BFF57AFC149
PowerPC PReP boot 9E1A2D38-C612-4316-AA26-8B49521E5A8B OSes (Linux, etc.) Shared boot loader configuration[76] BC13C2FF-59E6-4262-A352-B275FD6F7172
Atari TOS Basic data partition (GEM, BGM, F32) 734E5AFE-F61A-11E6-BC64-92361F002671
VeraCrypt Encrypted data partition 8C8F8EFF-AC95-4770-814A-21994F2DBC8F
OS/2 ArcaOS Type 1 90B6FF38-B98F-4358-A21F-48F35B4A8AD3
Storage Performance Development Kit (SPDK) SPDK block device[77] 7C5222BD-8F5D-4087-9C00-BF9843C7B58C
barebox bootloader barebox-state[78] 4778ED65-BF42-45FA-9C5B-287A1DC4AAB1
U-Boot bootloader U-Boot environment[79][80] 3DE21764-95BD-54BD-A5C3-4ABE786F38A8
SoftRAID[citation needed] SoftRAID_Status B6FA30DA-92D2-4A9A-96F1-871EC6486200
SoftRAID_Scratch 2E313465-19B9-463F-8126-8A7993773801
SoftRAID_Volume FA709C7E-65B1-4593-BFD5-E71D61DE9B02
SoftRAID_Cache BBBA6DF5-F46F-4A89-8F59-8765B2727503
Fuchsia standard partitions[81] Bootloader (slot A/B/R) FE8A2634-5E2E-46BA-99E3-3A192091A350
Durable mutable encrypted system data D9FD4535-106C-4CEC-8D37-DFC020CA87CB
Durable mutable bootloader data (including A/B/R metadata) A409E16B-78AA-4ACC-995C-302352621A41
Factory-provisioned read-only system data F95D940E-CABA-4578-9B93-BB6C90F29D3E
Factory-provisioned read-only bootloader data 10B8DBAA-D2BF-42A9-98C6-A7C5DB3701E7
Fuchsia Volume Manager 49FD7CB8-DF15-4E73-B9D9-992070127F0F
Verified boot metadata (slot A/B/R) 421A8BFC-85D9-4D85-ACDA-B64EEC0133E9
Zircon boot image (slot A/B/R) 9B37FFF6-2E58-466A-983A-F7926D0B04E0
Fuchsia legacy partitions[81][l]
fuchsia-esp C12A7328-F81F-11D2-BA4B-00A0C93EC93B
fuchsia-system 606B000B-B7C7-4653-A7D5-B737332C899D
fuchsia-data 08185F0C-892D-428A-A789-DBEEC8F55E6A
fuchsia-install 48435546-4953-2041-494E-5354414C4C52
fuchsia-blob 2967380E-134C-4CBB-B6DA-17E7CE1CA45D
fuchsia-fvm 41D0E340-57E3-954E-8C1E-17ECAC44CFF5
Zircon boot image (slot A) DE30CC86-1F4A-4A31-93C4-66F147D33E05
Zircon boot image (slot B) 23CC04DF-C278-4CE7-8471-897D1A4BCDF7
Zircon boot image (slot R) A0E5CF57-2DEF-46BE-A80C-A2067C37CD49
sys-config 4E5E989E-4C86-11E8-A15B-480FCF35F8E6
factory-config 5A3A90BE-4C86-11E8-A15B-480FCF35F8E6
bootloader 5ECE94FE-4C86-11E8-A15B-480FCF35F8E6
guid-test 8B94D043-30BE-4871-9DFA-D69556E8C1F3
Verified boot metadata (slot A) A13B4D9A-EC5F-11E8-97D8-6C3BE52705BF
Verified boot metadata (slot B) A288ABF2-EC5F-11E8-97D8-6C3BE52705BF
Verified boot metadata (slot R) 6A2460C3-CD11-4E8B-80A8-12CCE268ED0A
misc 1D75395D-F2C6-476B-A8B7-45CC1C97B476
emmc-boot1 900B0FC5-90CD-4D4F-84F9-9F8ED579DB88
emmc-boot2 B2B2E8D1-7C10-4EBC-A2D0-4614568260AD

See also


  1. ^ Adding ULL suffix to an integer constant makes it of type unsigned long long int.
  2. ^ Third party implementation exists (GPTTSD)
  3. ^ Only if using its service pack 1 or 2
  4. ^ In a multi-disk setup, non-UEFI bootloader (boot drive) requires MBR-based partitioning, while a system drive can use GUID partitioning.
  5. ^ The GUIDs in this table are written as per RFC 4122, i.e. big-endian byte order, recognizable by the position of the version bits. For example, the GUID for an EFI System partition (C12A7328-F81F-11D2-BA4B-00A0C93EC93B), when serialized in GPT data structures (little-endian), corresponds to the hex sequence 28 73 2A C1 1F F8 D2 11 BA 4B 00 A0 C9 3E C9 3B. The first three blocks are byte-swapped to little-endian, the last is a byte array. See details in TN2166[12]
  6. ^ The formation of this GUID does not follow the GUID definition; it is formed by using the ASCII codes for the string "Hah!IdontNeedEFI". Such formation of "GUID" value breaks down the guaranteed uniqueness of GUID.
  7. ^ a b Some computer manufacturers have their own GUIDs for partitions that are analogous to the EFI System Partition, but that hold boot loaders to launch manufacturer-specific recovery tools.[43]
  8. ^ a b Previously, Linux used the same GUID for the data partitions as Windows (Basic data partition: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7). Linux never had a separate unique partition type GUID defined for its data partitions. This created problems when dual-booting Linux and Windows in UEFI-GPT setup. The new GUID (Linux filesystem data: 0FC63DAF-8483-4772-8E79-3D69D8477DE4) was defined jointly by GPT fdisk and GNU Parted developers.[45] It is identified as type code 0x8300 in GPT fdisk.
  9. ^ a b The GUID for /usr on Solaris is used as a generic GUID for ZFS by macOS.
  10. ^ a b NetBSD and MidnightBSD had used the FreeBSD GUIDs before their unique GUIDs were created.
  11. ^ The Ceph filesystem uses GUIDs to mark the state of preparation a disk is in.[66][67]
  12. ^ The legacy Fuchsia GUIDs had two oddities: UUIDs were not generated randomly (several runs of bits were common between partitions), and partitions were uniquely identified by type GUID. The standardized scheme uses randomly-generated GUIDs, and slotted partitions (e.g. zircon_{a,b,r}) share the same type and are distinguished by name and unique GUID.[82]


  1. ^ a b "FAQ: Drive Partition Limits" (PDF). 2010. Retrieved 12 December 2020.
  2. ^ a b c "Unified Extensible Firmware Interface (UEFI) Specification" (PDF). 29 August 2022. p. 110. Retrieved 23 June 2023.
  3. ^ Swinburne, Richard (1 April 2010). "The Facts: 4K Advanced Format Hard Disks". Retrieved 12 December 2020.
  4. ^ Smith, Ryan (18 December 2009). "Western Digital's Advanced Format: The 4K Sector Transition Begins". Archived from the original on 28 December 2020. Retrieved 12 December 2020.((cite web)): CS1 maint: bot: original URL status unknown (link)
  5. ^ "Western Digital's Advanced Format: The 4K Sector Transition Begins". Anandtech.
  6. ^ "Enterprise Capacity 3.5 HDD Data Sheet" (PDF). Seagate Technology. April 23, 2014. p. 2. Archived (PDF) from the original on 2014-08-12. Retrieved August 10, 2014.
  7. ^ "WD Re Datacenter Distribution Specification Sheet" (PDF). Western Digital. January 21, 2016. p. 2. Archived (PDF) from the original on 2015-09-06. Retrieved February 14, 2016.
  8. ^ "Advanced format (4K) disk compatibility update (Windows)". November 28, 2012. Archived from the original on 2013-01-11. Retrieved January 3, 2013.
  9. ^ "Microsoft support policy for 4K sector hard drives in Windows". Microsoft. Archived from the original on 2011-08-19. Retrieved October 24, 2013.
  10. ^ "UEFI specification".
  11. ^ a b c d Smith, Roderick (3 July 2012). "Make the most of large drives with GPT and Linux". IBM. Retrieved 14 December 2020.
  12. ^ a b c d "Technical Note TN2166: Secrets of the GPT". Apple Developer. Apple. 2006-11-06. Retrieved 2014-04-16.
  13. ^ The GPT header contains a field that specifies the size of a partition table entry. The minimum required is 128 bytes, but implementations must allow for other values. See "Mac Developer Library". Apple. Retrieved 2014-07-13.
  14. ^ Leach, P.; Mealling, M.; Salz, R. (July 2005). A Universally Unique IDentifier (UUID) URN Namespace. Internet Engineering Task Force. doi:10.17487/RFC4122. RFC 4122. Retrieved 18 December 2020.
  15. ^ Elliott, Rob (4 January 2010). "e09127r3 EDD-4 Hybrid MBR Boot Code Annex" (PDF). Archived from the original (PDF) on 20 August 2020. Retrieved 16 December 2020.
  16. ^ "GPT | Microsoft Docs".
  17. ^ "CREATE_PARTITION_PARAMETERS (vds.h) - Win32 apps | Microsoft Docs".
  18. ^ "Disk Format". Retrieved 2022-02-09.
  19. ^ "Ubuntu on MacBook". Community Documentation. Ubuntu.
  20. ^ "GNU Parted FAQ".
  21. ^ "mklabel". Parted Manual. GNU.
  22. ^ "fdisk: add GPT support". 2013-09-27. Retrieved 2013-10-18.
  23. ^ Bueso, Davidlohr (2013-09-28). "fdisk updates and GPT support". Retrieved 2013-10-18.
  24. ^ "DISK_MAX_PARTS define". Archived from the original on 2020-03-26. Retrieved 2020-03-26.
  25. ^ "Myths and Facts About Intel Macs". rEFIt. Source forge.
  26. ^ "Significant changes from NetBSD 5.0 to 6.0"..
  27. ^ "Significant changes from NetBSD 5.0 to 6.0 (NetBSD/i386)"..
  28. ^ "Significant changes from NetBSD 5.0 to 6.0 (NetBSD/amd64)"..
  29. ^ "OpenBSD 5.9"..
  30. ^ "Booting from a ZFS Root File System". Oracle.
  31. ^ "idisk(1M)". Hewlett-Packard.
  32. ^ a b c d "Windows and GPT FAQ". 1 June 2017. Retrieved 14 December 2020.
  33. ^ Windows 8 32-bit supports booting from UEFI-based PC (x86-32 only) using GPT-based disks.
  34. ^ Windows 8.1 32-bit supports booting from UEFI-based PC (x86-32 only) using GPT-based disks.
  35. ^ Windows 10 32-bit supports booting from UEFI-based PC (x86-32 only) using GPT-based disks.
  36. ^ Microsoft raises the speed limit with the availability of 64-bit editions of Windows Server 2003 and Windows XP Professional Archived 2010-11-10 at the Wayback Machine
  37. ^ Windows 8 64-bit supports booting from UEFI-based PC (x86-64 only) using GPT-based disks.
  38. ^ Windows 8.1 64-bit supports booting from UEFI-based PC (x86-64 only) using GPT-based disks.
  39. ^ Windows 10 64-bit supports booting from UEFI-based PC (x86-64 only) using GPT-based disks.
  40. ^ Microsoft's 'Weirdest Release': Windows Server 2022 Quietly Becomes Generally Available
  41. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2013-07-28.((cite web)): CS1 maint: archived copy as title (link)
  42. ^ "F6F: Funtoo Linux and Intel Rapid Start Technology". 2012-10-30. Retrieved 2014-01-29.
  43. ^ GPT fdisk:, line 198
  44. ^ a b c d e "PARTITION_INFORMATION_GPT - Win32 apps". Microsoft Docs. Retrieved 2021-08-21.
  45. ^ Smith, Rod (23 June 2011). "Need for a unique Linux GPT GUID type code (PATCH included)". bug-parted (Mailing list). Retrieved 12 April 2016.
  46. ^ Sergei Antonov (2014-07-31). "libfdisk: (gpt) add Microsoft Storage Spaces GUID". util-linux/util-linux.git - The util-linux code repository. Retrieved 2021-08-21.
  47. ^ Known issues with Storage Replica
  48. ^ a b c d e f g h i The Discoverable Partitions Specification (DPS)
  49. ^ a b c d e f g h i systemd-gpt-auto-generator(8)
  50. ^ Home Directories
  51. ^ The Boot Loader Specification
  52. ^ a b "[dm-crypt] LUKS GPT GUID". Archived from the original on 2014-02-03. Retrieved 2014-01-29.
  53. ^ a b "[dm-crypt] LUKS GPT GUID". Archived from the original on 2014-02-03. Retrieved 2014-01-29.
  54. ^ a b "pyuefi source code".
  55. ^ "udisks-2.7.4 source code". GitHub. 10 July 2022.
  56. ^ The GNU/Hurd User's Guide: Installing, Internet Install
  57. ^ Hurd and GRUB use the same Linux ext2 file system to run and it no longer supports "UFS". file system
  58. ^ Hurd uses the same Linux swap file system
  59. ^ a b c d e f "FreeBSD System Manager's Manual gpart(8)". Retrieved 2021-08-21.
  60. ^ "Add a partition type for nandfs to the apm, bsd, gpt and vtoc8 schemes. · freebsd/freebsd-src@f24a822 · GitHub". GitHub. Retrieved 2021-08-21.
  61. ^ "CVS log for src/sys/sys/disklabel_gpt.h". Retrieved 2014-01-29.
  62. ^ "Disk Format - The Chromium Projects". Retrieved 2014-01-29.
  63. ^ "Constants and IDs". CoreOS. Retrieved 2018-07-26.
  64. ^ src/add-ons/kernel/partitioning_systems/gpt/gpt_known_guids.h
  65. ^;r2=1.5[permanent dead link] src/sys/sys/gpt.h
  66. ^ Script to set up a ceph disk: ceph-disk, lines 76-81
  67. ^ ceph-disk labels
  68. ^ QNX Power-safe filesystem
  69. ^ "gpt.ini (". GitHub.
  70. ^ "gpt.ini (". GitHub.
  71. ^ "gpt.ini (". GitHub.
  72. ^ "gpt-sample.ini (". GitHub.
  73. ^ " (".
  74. ^ "gpt.c (". GitHub.
  75. ^ " (". GitHub.
  76. ^ "The Boot Loader Specification". Retrieved 2017-01-05.
  77. ^ "SPDK Block Device User Guide". Retrieved 2021-01-20.
  78. ^ "Barebox State Framework". Retrieved 2021-05-21.
  79. ^ Villemoes, Rasmus (2020-11-17). "RFC: Partition type GUID for U-Boot environment". U-Boot mailing list (Mailing list). Retrieved 2021-09-28.
  80. ^ "U-boot 2021.07 source code: include/part_efi.h". Retrieved 2021-09-28.
  81. ^ a b zircon/system/public/zircon/hw/gpt.h
  82. ^ "[paver] add support for new partition scheme". Retrieved 2021-10-22.