2.6.2.6 Parent Locator

The parent locator specifies the type of the parent virtual block device as a GUID and a set of key-value pairs specifying anything necessary to locate and connect to the parent block device.

When the HasParent field of the file-parameters metadata item is set, there MUST be a parent locator. This metadata item specifies the identity and location of a parent virtual block device, whether this device is another VHDX file, a different type of virtual disk file, a logical unit in a SAN, or otherwise.

This specification describes only one such parent locator type (see section 2.6.2.6.3), but other implementations can extend this as required.

The parent locator item is made up of a 20-byte header immediately followed by a table of 12-byte entries specifying the offset and length of each key and value.