Mount/Dismount (0x0004)
Brings the media inside a physical device online or offline.
This operation assumes that the media is present. This operation identifies or verifies the media in the device.
This is not related to a NetWare volume mounting operation.
IMPORTANT:When acting on a mount request, the CDM must call CDI_Object_Update before completing the request with a call to CDI_Complete_Message. When acting on a dismount request, the CDM must call CDI_Complete_Message before calling CDI_Object_Update.