In Lenovo Storage V series, LUN 0, which is needed for all LUNs recognition, is represented as a regular disk on OpenVMS hosts. LUN 0 must be attached to the host at all times.
In Lenovo Storage V series and in other storage products, LUN 0 is used as the Command Console LUN (CCL), or pass-through LUN.
OpenVMS hosts require volumes with SCSI LUN 0 to be mapped. This action enables an OpenVMS host to recognize any other volumes mapped to the host. By default, the lowest available SCSI LUN ID is used when mapping a volume to a host. However, you can also set the SCSI LUN ID manually when creating a mapping by using the -scsi parameter. The following example creates a mapping with SCSI LUN ID 0:
mkvdiskhostmap -host host_name|host_id -scsi 0 vdisk_name|vdisk_id