Configure EVC to ensure that virtual machine migrations between hosts in the cluster do not fail because of CPU feature incompatibilities.

Before you begin

  • Verify that all hosts in the cluster have supported CPUs for the EVC mode you want to enable. See http://kb.vmware.com/kb/1003212 for a list of supported CPUs.

  • Verify that all hosts in the cluster are connected and registered on vCenter Server. The cluster cannot contain a disconnected host.

  • Virtual machines must be in the following power states, depending on whether you raise or lower the EVC mode.

    EVC Mode

    Virtual Machine Power Action

    Raise the EVC mode to a CPU baseline with more features.

    Running virtual machines can remain powered on. New EVC mode features are not available to the virtual machines until they are powered off and powered back on again. A full power cycling is required. Rebooting the guest operating system or suspending and resuming the virtual machine is not sufficient.

    Lower the EVC mode to a CPU baseline with fewer features.

    Power off virtual machines if they are powered on and running at a higher EVC Mode than the one you intend to enable.

    To verify the EVC mode for virtual machines, see Determine EVC Modes for Virtual Machines in the vSphere Web Client.

About this task

Several EVC approaches are available to ensure CPU compatibility:

  • If all the hosts in a cluster are compatible with a newer EVC mode, you can change the EVC mode of an existing EVC cluster.

  • You can enable EVC for a cluster that does not have EVC enabled.

  • You can raise the EVC mode to expose more CPU features.

  • You can lower the EVC mode to hide CPU features and increase compatibility.

Procedure

  1. Select a cluster in the inventory.
  2. Click the Manage tab and click Settings.
  3. Select VMware EVC and click Edit.
  4. Select whether to enable or disable EVC.

    Option

    Description

    Disable EVC

    The EVC feature is disabled. CPU compatibility is not enforced for the hosts in this cluster.

    Enable EVC for AMD Hosts

    The EVC feature is enabled for AMD hosts.

    Enable EVC for Intel Hosts

    The EVC feature is enabled for Intel hosts.

  5. From the VMware EVC Mode drop-down menu, select the baseline CPU feature set that you want to enable for the cluster.

    If you cannot select the EVC Mode, the Compatibility pane displays the reason, and the relevant hosts for each reason.

  6. Click OK.