Verify :

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.

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.

1.From the VMware EVC Mode drop-down menu, select the baseline CPU feature set that you want to enable for the cluster.
2.If you cannot select the EVC Mode, the Compatibility pane displays the reason, and the relevant hosts for each reason.
Click OK.

About this task:

Several EVC approaches are available to ensure CPU compatibility:

1.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.
2.You can enable EVC for a cluster that does not have EVC enabled.
3.You can raise the EVC mode to expose more CPU features.
4.You can lower the EVC mode to hide CPU features and increase compatibility.

vCenter Server places limits on the number of simultaneous virtual machine migration and provisioning operations that can occur on each host, network, and datastore. Each operation, such as a migration with vMotion or cloning a virtual machine, is assigned a resource cost. Each host, datastore, or network resource, has a maximum cost that it can support at any one time. Any new migration or provisioning operation that causes a resource to exceed its maximum cost does not proceed immediately, but is queued until other operations complete and release resources. Each of the network, datastore, and host limits must be satisfied for the operation to proceed.

Network Limits:

Network limits apply only to migrations with vMotion. Network limits depend on the version of ESXi and the network type. All migrations with vMotion have a network resource cost of 1.

Network Limits for Migration with vMotion

Operation

ESXi Version

Network Type

Maximum Cost

vMotion

5.0, 5.1, 5.5, 6.0

1GigE

4

vMotion

5.0, 5.1, 5.5, 6.0

10GigE

8

Datastore Limits:

Datastore limits apply to migrations with vMotion and with Storage vMotion. A migration with vMotion has a resource cost of 1 against the shared virtual machine’s datastore. A migration with Storage vMotion has a resource cost of 1 against the source datastore and 1 against the destination datastore.

vMotion

5.0, 5.1, 5.5, 6.0

128

1

Storage vMotion

5.0, 5.1, 5.5, 6.0

128

16

Host Limits: >>

Host limits apply to migrations with vMotion, Storage vMotion, and other provisioning operations such as cloning, deployment, and cold migration. >> All hosts have a maximum cost per host of 8. For example, on an ESXi 5.0 host, you can perform 2 Storage vMotion operations, or 1 Storage vMotion and 4 vMotion operations.

Host Migration Limits and Resource Costs for vMotion, Storage vMotion, and Provisioning Operations

Operation

ESXi Version

Derived Limit Per Host

Host Resource Cost

vMotion

5.0, 5.1, 5.5, 6.0

8

1

Storage vMotion

5.0, 5.1, 5.5, 6.0

2

4

vMotion Without Shared Storage

5.1, 5.5, 6.0

2

4

Other provisioning operations

5.0, 5.1, 5.5, 6.0

8

1