vixError = VixDiskLib_ReadMetadata(disk.Handle(), appGlobals.metaKey, &val[0], requiredLen, NULL);

Retrieves the value of a given key from disk metadata. The metadata for a hosted VMDK is not as extensive as for managed disk on an ESXi host. Held in a mapping file, VMFS metadata might also contain information such as disk label, LUN or partition layout, number of links, file attributes, locks, and so forth. Metadata also describes encapsulation of raw disk mapping (RDM) storage, if applicable.