About Host Groups
Applies To: Virtual Machine Manager 2008, Virtual Machine Manager 2008 R2, Virtual Machine Manager 2008 R2 SP1
You can create custom groups of virtual machine hosts, known as host groups, for grouping hosts and their virtual machines in meaningful ways. For example, you might create a host group for each branch office in your organization. You can also use host groups to set aside resources on hosts in the host group for the use of the host operating system. Host groups are represented by folders in the navigation pane of the Hosts view and Virtual Machines view. Host groups are created by using the New host group action in both of those views.
When you add a VMware VirtualCenter Server, all existing hosts for that server are also added and automatically placed into host groups that match the datacenter hierarchy on the server. A host group is created for each folder and host cluster within each datacenter. VMware ESX servers must remain within their parent host group or a child of that host group. If a new datacenter is subsequently added, it appears as a new host group in Virtual Machine Manager (VMM) the next time the VMware VirtualCenter Server is refreshed.
Ways to Use Host Groups
The following list describes ways that you can create and use host groups to organize hosts for your environment:
Basic organization when managing large numbers of hosts and virtual machines—You can create custom views within the Hosts view and Virtual Machines view to provide easy monitoring and access to host groupings of your choice. For example, you might create a host group for each branch office in your organization.
Reserving resources for use by hosts—Host reserves are useful when virtual machines are placed on a host. The host reserves determine the amount of CPU, memory, disk space, disk I/O capacity, and network capacity that will always be available to the host operating system. Use the Host group properties action for the root host group, All Hosts, to set default host reserves for all hosts managed by Virtual Machine Manager. If you want to use the resources on some hosts more fully than on other hosts, you can set host reserves differently for each host group.
Designating hosts on which users can create and operate their own virtual machines—When a VMM administrator adds self-service roles, the role identifies the hosts on which self-service users or groups in that role are allowed to create, operate, and manage their own virtual machines. This process is known as virtual machine self-service. It is easier to designate such hosts if a specific host group is created for this purpose. For more information, see About Virtual Machine Self-Service.
Implementing Performance and Resource Optimization (PRO)—PRO is implemented for individual host groups and host clusters. For more information, see About PRO (https://go.microsoft.com/fwlink/?LinkID=157194).
Creating a Host Group Hierarchy
Host groups are hierarchical. You can create a child host group within another host group. You can also add child host groups to a parent host group by using the Move action or by dragging host groups and dropping them into a parent host group. All host groups and all hosts belong to the All Hosts root host group, which is created during installation.
Inheritance of Host Group Settings
Within the host group hierarchy, child host groups can inherit settings from their parent host group.
The inheritance results from host group actions are explained in the following table.
| Host group action | Host reserves settings | PRO settings |
|---|---|---|
Create a new child host group within a parent host group or the root parent group All Hosts |
Child host group inherits the host reserve settings from its parent host group |
Child host group inherits the PRO settings from its parent host group |
Add a child host group to a parent host group or the root parent group All Hosts |
Child host group does not inherit the host reserve settings from its parent host group |
Child host group inherits the PRO settings from its parent host group if the Inherit PRO setting from parent Host Group check box is selected for the child host group |
Change the settings of a parent host group or the root parent group All Hosts |
You are given the option to apply host reserve changes to only the parent host group or to cascade the revised settings down to all child host groups Important If you choose to cascade the parent host reserve settings, all parent host reserve settings, not just the settings that were changed, will overwrite all settings for all child host groups of the parent host group. |
Child host groups inherit the PRO settings from its parent host group if the Inherit PRO setting from parent Host Group check box is selected for the child host group |
See Also
Concepts
Other Resources
How to Delete a Host Group
How to Modify the Properties of a Host Group