merging, a parser must destroy any metadata with this field set in the parent and copy all metadata with this field set in the child to the parent. The IsUser field specifies whether this metadata item is considered system or user metadata. Only up to 1024 entries may have this bit set; if more entries have this set, the metadata table is invalid. A parser should generally not allow users to query metadata items that have this bit set to False. The IsRequired field specifies whether the parser must understand this metadata item to be able load the file. If this field is set to True and the parser does not recognize this metadata item, the parser must fail to load the file. Known Metadata Items are certain Metadata items that are defined in this specification, some of which are optional and some of which are required. The table below summarizes the known metadata items and their optional or required state. Table : Known Metadata Item Properties Known GUID IsVirtualDisk IsUser IsRequired Items File CAA16737-FA36-4D43-B3B6-33F0AA44E76B False False True Parameters Virtual Disk 2FA54224-CD1B-4876-B211-5DBED83BF4B8 True True Size Page 83 BECA12AB-B2E6-4523-93EF-C309E000C746 True False True Data Logical 8141BF1D-A96F-4709-BA47-F233A8FAAB5F True True Sector Size Physical CDA348C7-445D-4471-9CC9-E9885251C556 True False True Sector Size Parent A8D35F2D-B30B-454D-ABF7-D3D84834AB0C False True Locator File Parameters Structure : File Parameters Metadata Item struct VHDX_FILE_PARAMETERS { UINT32 BlockSize; UINT32 LeaveBlocksAllocated:1; UINT32 HasParent:1; UINT32 Reserved:30; };
merging, a parser must destroy any metadata with this field set in the parent and copy all metadata with this field set in the child to the parent. The IsUser field specifies whether this metadata item is considered system or user metadata. Only up to 1024 entries may have this bit set; if more entries have this set, the metadata table is invalid. A parser should generally not allow users to query metadata items that have this bit set to False. The IsRequired field specifies whether the parser must understand this metadata item to be able load the file. If this field is set to True and the parser does not recognize this metadata item, the parser must fail to load the file. Known Metadata Items are certain Metadata items that are defined in this specification, some of which are optional and some of which are required. The table below summarizes the known metadata items and their optional or required state. Table : Known Metadata Item Properties Known Items GUID IsUser IsVirtualDisk IsRequired File Parameters CAA16737-FA36-4D43-B3B6-33F0AA44E76B False False True Virtual Disk Size 2FA54224-CD1B-4876-B211-5DBED83BF4B8 True True Page 83 Data BECA12AB-B2E6-4523-93EF-C309E000C746 False True True Logical Sector Size 8141BF1D-A96F-4709-BA47-F233A8FAAB5F True True Physical Sector Size CDA348C7-445D-4471-9CC9-E9885251C556 False True True Parent Locator A8D35F2D-B30B-454D-ABF7-D3D84834AB0C False True File Parameters Structure : File Parameters Metadata Item struct VHDX_FILE_PARAMETERS { UINT32 BlockSize; UINT32 LeaveBlocksAllocated:1; UINT32 HasParent:1; UINT32 Reserved:30; };
VHDX%20Format%20Specification-v1.00.docx