Newer generations of AMD processors do not include 3DNow! processor instructions. If hosts in a cluster have different generations of AMD processors, some with 3DNow! instruction sets and some without, you cannot successfully migrate virtual machines between the hosts. You must use an EVC mode or CPU compatibility mask to hide the instructions.
The vCenter Server AMD Opteron Gen. 3 (no 3DNow!) EVC mode masks the 3DNow! instructions from virtual machines. You can apply this EVC mode to EVC clusters containing only AMD Opteron Generation 3 hosts to allow the clusters to maintain vMotion compatibility with AMD Opteron hosts that do not have 3DNow! instructions. Clusters containing AMD Opteron Generation 1 or AMD Opteron Generation 2 hosts cannot be made vMotion-compatible with hosts that do not have 3DNow! instructions.
- You must be connected to a vCenter Server system with the vSphere Client.
- Ensure that the cluster contains only hosts with AMD Opteron Generation 3 or newer processors.
|Creating a new cluster||In the New Cluster wizard, enable EVC for AMD hosts and select the AMD Opteron Gen. 3 (no 3DNow!) EVC mode.|
|Editing a cluster without powered-on virtual machines||In the Cluster Settings dialog box, edit the VMware EVC settings and select the AMD Opteron Gen. 3 (no 3DNow!) EVC mode.|
|Editing a cluster with powered-on virtual machines||The AMD Opteron Gen. 3 (no 3DNow!) EVC mode cannot be enabled while there are powered-on virtual machines in the cluster.
You can now add hosts with AMD processors without 3DNow! instructions to the cluster and preserve vMotion compatibility between the new hosts and the existing hosts in the cluster.