6.7

Table Of Contents
EVC cannot prevent virtual machines from accessing hidden CPU features in all circumstances.
Applications that do not follow CPU vendor recommended methods of feature detection might behave
unexpectedly in an EVC environment. VMware EVC cannot be supported with ill-behaved applications
that do not follow the CPU vendor recommendations. For more information about creating well-behaved
applications, search the VMware Knowledge Base for the article Detecting and Using New Features in
CPUs.
EVC Requirements for Hosts
To improve CPU compatibility between hosts that have varying CPU feature sets, you can hide some host
CPU features from the virtual machines by placing the host in an Enhanced vMotion Compatibility (EVC)
cluster. Hosts in an EVC cluster and hosts that you add to an existing EVC cluster must meet EVC
requirements.
n
Power off all virtual machines in the cluster that are running on hosts with a feature set greater than
the EVC mode that you intend to enable. You can also migrate these virtual machines out of the
cluster.
n
All hosts in the cluster must meet the following requirements:
Requirements Description
Supported ESXi version ESXi 6.0 or later.
vCenter Server The host must be connected to a vCenter Server system.
CPUs A single vendor, either AMD or Intel.
Advanced CPU features
enabled
Enable these CPU features in the BIOS if they are available:
n
Hardware virtualization support (AMD-V or Intel VT)
n
AMD No eXecute(NX)
n
Intel eXecute Disable (XD)
Note Hardware vendors sometimes disable particular CPU features in the BIOS by default. You might
have problems enabling EVC because the EVC compatibility checks detect the absence of features that
are expected to be present for a particular CPU. If you cannot enable EVC on a system with a
compatible processor, ensure that all features are enabled in the BIOS.
Supported CPUs for the
EVC mode that you
want to enable
To check EVC support for a specific processor or server model, see the VMware Compatibility Guide at
http://www.vmware.com/resources/compatibility/search.php.
Configured for vMotion See Host Configuration for vMotion.
Create an EVC Cluster
Create an EVC cluster to ensure vMotion CPU compatibility between the hosts in the cluster.
To create an EVC cluster with minimal disruption to your existing infrastructure, create an empty EVC
cluster and move hosts into the cluster. To enable EVC on an existing cluster, see Enable EVC on an
Existing Cluster.
Other cluster features such as vSphere DRS and vSphere HA are fully compatible with EVC. You can
enable these features when you create the cluster.
vCenter Server and Host Management
VMware, Inc. 137