vCenter Server provides features that help ensure that virtual machines migrated with VMotion meet processor
compatibility requirements. These features include:
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Enhanced VMotion Compatibility (EVC) – You can use EVC to help ensure VMotion compatibility for the
hosts in a cluster. EVC ensures that all hosts in a cluster present the same CPU feature set to virtual
machines, even if the actual CPUs on the hosts differ. This prevents migrations with VMotion from failing
due to incompatible CPUs.
Configure EVC from the Cluster Settings dialog box. The hosts in a cluster must meet certain requirements
for the cluster to use EVC. For more information on EVC and EVC requirements, see Basic System
Administration.
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CPU compatibility masks – vCenter Server compares the CPU features available to a virtual machine with
the CPU features of the destination host to determine whether to allow or disallow migrations with
VMotion. By applying CPU compatibility masks to individual virtual machines, you can hide certain CPU
features from the virtual machine and potentially prevent migrations with VMotion from failing due to
incompatible CPUs.
VMotion Requirements
To enable the use of DRS migration recommendations, the hosts in your cluster must be part of a VMotion
network. If the hosts are not in the VMotion network, DRS can still make initial placement recommendations.
To be configured for VMotion, each host in the cluster must meet the following requirements:
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The virtual machine configuration file for ESX/ESXi hosts must reside on a VMware Virtual Machine File
System (VMFS).
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VMotion does not support raw disks or migration of applications clustered using Microsoft Cluster Service
(MSCS).
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VMotion requires a private Gigabit Ethernet migration network between all of the VMotion enabled
managed hosts. When VMotion is enabled on a managed host, configure a unique network identity object
for the managed host and connect it to the private migration network.
Create a DRS Cluster
Create a DRS cluster using the New Cluster wizard in the vSphere Client.
Prerequisites
You can create a cluster without a special license, but you must have a license to enable a cluster for DRS (or
VMware HA).
Procedure
1 Right-click a datacenter or folder in the vSphere Client and select New Cluster.
2 Name the Cluster in the Name field.
This name appears in the vSphere Client inventory panel.
3 Enable the DRS feature by clicking the VMware DRS box.
You can also enable the VMware HA feature by clicking VMware HA.
4 Click Next.
vSphere Resource Management Guide
48 VMware, Inc.
