Set-SCVMHostCluster

Modifies the properties of a virtual machine host cluster managed by VMM.

Syntax

Set-SCVMHostCluster [-VMHostCluster] <HostCluster> [-ClusterReserve <UInt32>] [-Description <String>]
 [-JobGroup <Guid>] [-JobVariable <String>] [-PROTipID <Guid>] [-RunAsynchronously]
 [-SetQuorumDisk <ClientObject>] [-SetQuorumNodeMajority] [-VMHostManagementCredential <VMMCredential>]
 [<CommonParameters>]

Description

The Set-SCVMHostCluster cmdlet modifies the properties of a host cluster managed by Virtual Machine Manager (VMM). Properties that you can modify include changing the cluster reserve setting.

The ClusterReserve parameter specifies the number of host failures that a host cluster can sustain before VMM considers the cluster to be over-committed. An over-committed host cluster is one that cannot withstand the specified number of host failures and keep all of the virtual machines in the cluster running.

VMM uses the following processes to determine over-commitment:

- Host Placement. The placement process calculates whether adding a new virtual machine to the host cluster will over-commit the host cluster and, if so, placement stops recommending the deployment of additional virtual machines on hosts in that cluster.

  • Cluster Refresher. The host cluster refresher calculates, at periodic intervals, whether a host cluster is over-committed or not based on the following events:

    - A change in the value specified for the ClusterReserve parameter.
    • The failure or removal of nodes from the host cluster.
    • The addition of nodes to the host cluster.
    • The discovery of new virtual machines on nodes in the host cluster.

      The following examples illustrate how over-commitment works.

      Example 1: Over-commitment when all nodes are functioning

      If you specify a cluster reserve of 2 for an 8-node host cluster, and all 8 nodes are functioning, the host cluster is over-committed if any combination of 6 (8 minus 2) nodes lacks the capacity to accommodate existing virtual machines.

      Example 2: Over-commitment when some nodes are not functioning

      If you specify a cluster reserve of 2 for an 8-node host cluster, but only 5 nodes are functioning, the host cluster is over-committed if any combination of 3 (5 minus 2) nodes lacks the capacity to accommodate existing virtual machines.

Examples

Example 1: Change the setting for the cluster reserve for a host cluster

PS C:\> $VMHostCluster = Get-SCVMHostCluster -Name "VMHostCluster01.Contoso.com"
PS C:\> Set-SCVMHostCluster -VMHostCluster $VMHostCluster -ClusterReserve 2

The first command gets the host cluster object named VMHostCluster01.Contoso.com and stores the object in the $VMHostCluster variable.

The second command changes the value for the cluster reserve for host cluster VMHostCluster01 to 2.

Parameters

-ClusterReserve

Specifies the number of host failures that a host cluster can sustain before VMM designates the cluster as over-committed. The default value is 1.

Type:UInt32
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Description

States a description for the specified object.

Type:String
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-JobGroup

Specifies an identifier for a series of commands that will run as a set just before the final command that includes the same job group identifier runs.

Type:Guid
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-JobVariable

Specifies that job progress is tracked and stored in the variable named by this parameter.

Type:String
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-PROTipID

Specifies the ID of the Performance and Resource Optimization tip (PRO tip) that triggered this action. This parameter lets you audit PRO tips.

Type:Guid
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-RunAsynchronously

Indicates that the job runs asynchronously so that control returns to the command shell immediately.

Type:SwitchParameter
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-SetQuorumDisk

Specifies a disk to use as the quorum disk for the cluster.

Type:ClientObject
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-SetQuorumNodeMajority

Sets the quorum mode to Node Majority for the cluster.

Type:SwitchParameter
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-VMHostCluster

Specifies a VMM host cluster object.

Type:HostCluster
Required:True
Position:0
Default value:None
Accept pipeline input:True (ByValue)
Accept wildcard characters:False
-VMHostManagementCredential

This parameter is obsolete.

Type:VMMCredential
Required:False
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False

Outputs

VMHostCluster

This cmdlet returns a **VMHostCluster** object.