Create host cluster

You can use the management GUI to create a host cluster. A host cluster is a group of logical host objects that can be managed together. For example, you can create a volume mapping that is shared by every host in the host cluster. The systems use internal protocols to manage access to the volumes and ensure consistency of the data.

When you create a host cluster, you can specify the hosts to include in the cluster. You can also create an empty host cluster and add hosts later. If you select hosts to add to the host cluster, all of the common private volume mappings for the hosts become shared mappings for the host cluster. However, you can also exclude specific volumes from being shared. The private volume mappings are not shared with any other hosts in the host cluster. A host can be a member of only one host cluster.

With shared mapping, volumes are mapped on a host cluster basis. The volumes are shared by all of the hosts in the host cluster.

To create a host cluster, complete these steps:

On the Host Cluster page, select Create Host Cluster.
On the Create Host Cluster page, enter the name of the host cluster that you want to create.
Select the available hosts to include within the host cluster. By default, any volumes that are mapped to all the selected hosts become a shared mapping for the host cluster, which each of the hosts inherit. Any new volume mappings that are added to the host cluster are inherited by each host in the host cluster. You can also choose to create an empty host cluster to add individual hosts later. See Add a host member to a host cluster for details.
Click Next.
If you selected hosts to add to the host cluster, you can exclude specific volumes that are already mapped to these hosts. These volumes are retained as private mappings to the individual hosts in the host cluster but do not become shared mappings for the entire host cluster. New hosts that are added to the host cluster do not inherit these volume mappings. Select any volumes that you want to remain private mappings.
If throttles are configured on any of the selected hosts, the throttles must be removed to be included in the host cluster. Throttles can be applied only to the host cluster and not individual hosts within the cluster. If you choose not to remove the throttles from the host, the host is excluded from the host cluster. See Throttles for hosts and host clusters for details.
Click Next.
On the Summary page, verify the settings and click Create Host Cluster.
Note: If you selected hosts with volumes that have SCSI ID conflicts, the system does not add these mappings to the host cluster. A SCSI LUN ID conflict occurs when multiple hosts are mapped to the same volume but with different SCSI IDs. In this case, a shared mapping is not created because the system does not allow a volume to be mapped more than once to the same host. The Summary page lists all volumes that contain conflicts and the system retains these mappings as private mappings to the original hosts.