... ... ... DataWriteGuid ... ... ... LogGuid ... ... ... Version LogVersion LogLength LogOffset ... Reserved (4016 Signature (4 MUST be 0x64616568 ("head" as UTF8). Checksum (4 A CRC-32C hash over the entire 4-KB structure, with the Checksum field taking the value of zero during the computation of the checksum value. SequenceNumber (8 A 64-bit unsigned integer. A header is valid if the Signature and Checksum fields both validate correctly. A header is current if it is the only valid header or if it is valid and its SequenceNumber field is greater than the other header's SequenceNumber field. The implementation MUST only use data from the current header. If there is no current header, then the VHDX file is corrupt. FileWriteGuid (16 bytes): Specifies a 128-bit unique identifier that identifies the file's contents. On every open of a VHDX file, an implementation MUST change this GUID to a new and unique identifier before the first modification is made to the file, including system and user metadata as well as log playback. The implementation can skip updating this field if the storage media on which the file is stored is read-only, or if the file is opened in read-only mode. DataWriteGuid (16 bytes): Specifies a 128-bit unique identifier that identifies the contents of the user visible data. On every open of the VHDX file, an implementation MUST change this field to a new and unique identifier before the first modification is made to user-visible data. If the user of
... ... ... DataWriteGuid ... ... ... LogGuid ... ... ... LogVersion Version LogLength LogOffset ... Reserved (4016 Signature (4 MUST be 0x64616568 ("head" as UTF8). Checksum (4 A CRC-32C hash over the entire 4-KB structure, with the Checksum field taking the value of zero during the computation of the checksum value. SequenceNumber (8 A 64-bit unsigned integer. A header is valid if the Signature and Checksum fields both validate correctly. A header is current if it is the only valid header or if it is valid and its SequenceNumber field is greater than the other header's SequenceNumber field. The implementation MUST only use data from the current header. If there is no current header, then the VHDX file is corrupt. FileWriteGuid (16 bytes): Specifies a 128-bit unique identifier that identifies the file's contents. On every open of a VHDX file, an implementation MUST change this GUID to a new and unique identifier before the first modification is made to the file, including system and user metadata as well as log playback. The implementation can skip updating this field if the storage media on which the file is stored is read-only, or if the file is opened in read-only mode. DataWriteGuid (16 bytes): Specifies a 128-bit unique identifier that identifies the contents of the user visible data. On every open of the VHDX file, an implementation MUST change this field to a new and unique identifier before the first modification is made to user-visible data. If the user of