partition-type-guid · shipping · also GPT partition type

Partition type GUID

A partition type GUID declares a GPT partition's purpose or content class and is distinct from the unique GUID identifying that individual partition.

Related Observatory article: Partition type GUID on hesela.com

Partitions of the same declared type can share a type GUID while having different UniquePartitionGUID values. The disk has a separate DiskGUID. A type label does not verify filesystem structures or authenticate their contents. [1]

The util-linux v2.41 sfdisk interface distinguishes --part-type, --part-uuid and --disk-id. Do not confuse a partition UUID with a filesystem's own identifier. When evaluating an acquired image, retain original identifiers as evidence; do not rewrite them merely to make a preservation copy look unique. [2]

Relations

related

GUID Partition Table (GPT), Protective MBR, Partition alignment

Limitations

• UEFI requires new disk and unique partition GUIDs for copied disks put into service; preserve original identifiers in the acquisition evidence and make operational identity changes on a separate copy. [1]
• Changing the declared type does not convert or repair the data stored in the partition. [2, 1]

Citations

1. UEFI 2.10, chapter 5: GPT layout, headers and partition entries (accessed 2026-10-21)
2. util-linux v2.41 sfdisk manual: partition type, partition UUID and disk ID (accessed 2026-10-21)

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