3.4 Installing the VM Recovery Manager HA solution The VM Recovery Manager HA solution provides HA management for IBM Power Systems  servers with PowerVM virtualization. After you plan the implementation of the VM Recovery  Manager HA solution, you can install the VM Recovery Manager HA software. The VM  Recovery Manager HA solution uses other subsystems such as HMC and VIOSs that must  exist in your production environment. The VM Recovery Manager HA software can be enabled when you have the following  subsystems in your production environment: Figure 3-4 shows the components of VM Recovery Manager HA. Figure 3-4 Components of VM Recover Manager HA  274  Implementing IBM VM Recovery Manager for IBM Power Systems GLYPH<SM590000> VIOS Version 3.1.0.1 or later must be installed on all VIOS partitions that are part of the  host group. Host Monitor (HM), which is a key component of the VM Recovery Manager  HA solution, is installed on the VIOS by default. The HM component is enabled and used  when you install the VM Recovery Manager HA filesets. The VM Recovery Manager HA  solution requires two VIOS per host. GLYPH<SM590000> HMC V9 R 9.1.0 or later must be used to manage all hosts that are part of the cluster.