Adding a VMware ESXi host to a VMware ESXi cluster with a CPU similar to Enhanced vMotion Compatibility baseline

Products

• VMware vSphere ESXi

Issue/Introduction

This article contains steps to add a VMware ESXi host, which has a CPU similar to that of the current Enhanced vMotion Compatibility (EVC) baseline, to an ESXi host cluster. This is due to new instruction sets being available in the different revisions. Although the processors will be the same EVC baseline, this is required for the processors to all present the same instruction sets to the virtual machines.

Environment

VMware vSphere ESXi 5.1
VMware vSphere ESXi 5.5
VMware vSphere ESXi 5.0

Resolution

To determine the EVC baseline to be used, see:

• EVC and CPU Compatibility FAQ (1005764)
• Cannot add an ESX/ESXi host with running virtual machines to an EVC enabled Cluster (1009571)

To add an ESXi host with an similar CPU to the current EVC baseline to an ESXi cluster:

1. To add the new ESXi host (or multiple ESXi hosts) in the EVC-enabled cluster, all virtual machines must be powered off on the ESXi host. This ensures the ESXi host(s) and the virtual machines can have their CPU instruction sets masked.
2. Place the new ESXi host in maintenance mode.
3. Add the new ESXi host to the existing EVC cluster in vCenter Server.
4. If the ESXi host is already added to vCenter Server, click and drag the new ESXi host to the EVC-enabled cluster.
5. Exit maintenance mode and power on any virtual machines on the ESXi host.

Note: Any virtual machine that was previously running on the new ESXi host will now have a different CPU instruction set presented.