Many of the actions that are described are available from different menus. For example, you  can select  Volumes  and its option  Volumes by Hosts , where you can also rename hosts.  This flexibility is one of the advantages of the enhanced, redesigned IBM Spectrum Virtualize  management GUI. 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 (see  Figure 3-64). The systems use internal protocols to manage access to the volumes and ensure consistency  of the data. Host objects that represent hosts can be grouped in a host cluster and share  access to volumes. New volumes can also be mapped to a host cluster, which simultaneously  maps that volume to all hosts that are defined in the host cluster. Each host cluster is  identified by a unique name and ID, the names of the individual host objects within the cluster,  and the status of the cluster.  A host cluster can contain up to 128 hosts. However, a host can be a member of only one  host cluster. The management GUI displays the status of each host cluster.  A host cluster can have one of the following statuses: 3.5.2 Host clusters Figure 3-64 Create Host Cluster window GLYPH<SM590000> Offline: All hosts in the host cluster are offline (or the host cluster does not contain any  hosts). GLYPH<SM590000> Host cluster degraded: At least one host is offline and at least one host is online or  degraded. GLYPH<SM590000> Host degraded: All hosts in the host cluster are online or degraded. GLYPH<SM590000> Online: All hosts in the host cluster are online. Chapter 3. Graphical user interface overview  131