Starting with IBM Spectrum Virtualize 8.1, host clusters can be added by using the GUI. For  more information, see  Implementing the IBM System Storage SAN Volume Controller with  IBM Spectrum Virtualize V8.2.1 , SG24-7933. For GUI users, when you use the  Map to Host or Host Cluster  function, it now allows you to  let the system assign the SCSI ID for the volume or to manually assign the SCSI ID. For ease  of management purposes, it is suggested to use separate ranges of SCSI IDs for hosts and  host clusters.  For example, you can use SCSI IDs 0 - 99 to non-cluster host volumes, and above 100 for the  cluster host volumes. When you choose the option  System Assign the system automatically  assigns the SCSI IDs starting from the first available in the sequence.  If you choose  Self Assign ,  the system enables you to select the SCSI IDs manually for each  volume, and on the right part of the screen it shows the SCSI IDs that are already used by the  selected host/host cluster, as shown in Figure 7-1. Note:  Although extra care is always recommended when dealing with hosts, IBM  Spectrum Virtualize does not allow you to join a host into a host cluster if it already has a  volume mapping with a SCSI ID that also exists in the host cluster, as shown below: IBM_FlashSystem:ITSO-FS9100:superuser>addhostclustermember -host ITSO_HOST3  ITSO_CLUSTER1 CMMVC9068E Hosts in the host cluster have conflicting SCSI ID's for their  private mappings. IBM_FlashSystem:ITSO-FS9100:superuser> Figure 7-1 SCSI ID assignment on volume mappings Chapter 7. Hosts  243