Where does the xenstore /local/domain/<device dom>/backend/vbd/<domu>/<vbd device>/uuid come from? In my case /local/domain/0/backend/vbd/335/51712/uuid = bdc23468-1ea6-f395-8ef0-67e45cb59009 and the corresponding lv uuid is k6HeO6-utKp-3mop-aaBp-vB4n-ykuI-Beptm6 but the latter is not a conventionally expressed UUID and at least as base64 doesn''t match the xentore uuid... I''m looking for something to tell Windows is a unique identifier for the disk Thanks James