Use the following procedure to change the name or description of a host group, move a host group within the host group hierarchy, or modify the resources reserved for the host operating system on the host. A virtual machine cannot be placed on a host if the virtual machine's resource requirements cannot be met without using the host reserves.

When you change the host reserve or PRO settings for a parent host group, the child host groups of that parent host group can inherit the changes from its parent host group. For more information about host group settings and inheritance, see About Host Groups.
To modify the properties of a host group
  1. In Hosts view, expand All Hosts in the navigation pane and then navigate to the host group that you want to modify.

  2. In the Actions pane, under Host Group, click Properties.

  3. On the General tab, you can update any of the following properties:

    • Optionally modify the host group name or description.

    • To move the host group within the host group hierarchy, click Move Host Group.

    • In VMM 2008 R2, you can allow unencrypted file transfers by selecting the Allow unencrypted file transfers check box. During future file transfers to and from hosts in the host group, the files will not be encrypted if unencrypted file transfers are allowed in VMM both on the source computer (a host, library server, or P2V source machine) and the destination computer (either a host or a library server). During physical-to-virtual machine conversions (P2V), unencrypted file transfers from the P2V source machine always are allowed if they also are allowed on the destination host.

  4. On the Host Reserves tab, optionally modify the default settings for the resources to be set aside for the host operating systems of new hosts. When a new host is added to Virtual Machine Manager (VMM), with this host group selected, the host inherits this host group’s default reserve settings. After you add the host, you can override the reserve settings for individual hosts.

  5. On the PRO tab, optionally modify settings for Performance and Resource Optimization (PRO) for hosts in the host group:

    1. To use the PRO settings for the host group’s parent host group, select the Inherit PRO settings from parent host group check box. If you choose not to use the parent host group’s PRO settings, complete the remaining steps to determine which PRO tips are received and which are automatically implemented for the host group.

    2. Select the Enable PRO on this host group check box.

    3. To determine which PRO tips will be received for this host group, select the severity level: Critical Only or Warning and Critical.

      You can have VMM automatically implement PRO tips—for example, VMM might automatically migrate a virtual machine to a different host when either host performance or virtual machine performance falls below a certain threshold—or you can choose to implement the PRO tips manually from the PRO Tips window. Some PRO tips require manual intervention.

    4. If you want to automatically implement PRO tips for the host group:

      • Select the Automatically implement PRO tips on this host group check box.

      • Select the severity of PRO tips that you want to automatically implement for the host group: Critical Only or Warning and Critical.

    The PRO properties are available only after you configure Operations Manager integration with VMM. For more information, see Configuring Operations Manager Integration with VMM ( For more information about PRO, see Enabling PRO in VMM 2008 (

See Also

For the most up-to-date Help information, go to the Virtual Machine Manager 2008 Help Online. To find additional Virtual Machine Manager 2008 documentation, go to the Virtual Machine Manager 2008 TechCenter Library.