The OpenVMS operating system considers a fibre-channel device with LUN ID 0 as Command Console LUN (CCL). These devices do not normally display when you issue the DS CLI lshostvol command. However, with adjustments, these devices can be displayed when you issue the lshostvol command. The following description provides the information that you need to make this enhancement work on your OpenVMS system.
Fibre-channel CCL devices have the OpenVMS device type GG, which result in OpenVMS device names in the form $1$GGAn. In contrast, fibre-channel disk devices have the OpenVMS device type DG, which result in device names in the form $1$DGAn. Therefore, LUN 0 devices on OpenVMS are a special device type, different from disk devices.
The DS CLI lshostvol command displays the mapping of host device names or volume names to machine type 2105, 2107, and 1750 volume IDs. That implies that all host devices belonging to 2105/2107/1750 volumes are displayed. Therefore, CCL devices $1$GGAn are included in the lshostvol output for multiplatform consistency and to match the output of other DS CLI commands.
However, the inclusion of CCL devices can be confusing for users who expect that the lshostvol command displays only the disk devices. You can use the OpenVMS logical name IBMDSCLI$SHOW_GG_DEVICES to modify the DS CLI behavior: If this logical name translates to an expression which evaluates as True in OpenVMS conventions (1, Y, YES, T, or TRUE), then the $1$GGAn CCL devices are shown in the command output. Otherwise, the $1$GGAn CCL devices are not shown.
The startup procedure IBMDSCLI$STARTUP.COM defines the logical name IBMDSCLI$SHOW_GG_DEVICES as Y. If you want to suppress $1$GGAn CCL devices in the lshostvol command output, you can redefine the logical name after the startup procedure has been processed.