Described is a technology by which a single physical storage device such as a USB flash memory device is able to boot different computing devices via corresponding different operating systems. The storage device includes a selection mechanism that determines which virtual disk (corresponding to a LUN) is seen by the host as the currently active LUN having sector 0, and therefore is the boot disk. The selection mechanism also may select which (if any) other LUNs are visible to the host. The selection mechanism and accompanying indicator may be operated when the storage device is disconnected, e.g., via manual switches and/or LEDs, buttons and/or a display (e.g., via internal power). Also described is allowing each LUN to have a user-friendly name.