Adding an ESXi host with an older CPU than the current EVC baseline

Products

• VMware vSphere ESXi

Issue/Introduction

This article contains steps to add an ESXi host that has an older CPU to the current Enhanced vMotion Compatibility (EVC) baseline to an ESXi cluster.

Environment

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

Resolution

Adding an ESXi host with an older CPU to a newer EVC baseline requires the baseline to be changed to match the oldest CPU in the ESXi cluster. This is due to the cluster needing to mask all of the newer CPU instruction sets provided from the newer generation CPUs in order for all CPUs to be presented with the same instruction sets to the virtual machines.

Note: This will require a maintenance window as the virtual machines must be powered off.

To determine the EVC baseline to be used, see:

• EVC and CPU Compatibility FAQ (1005764)
  
• Enabling EVC on a cluster when vCenter Server is running in a virtual machine (1013111)
  
• Enhanced vMotion Compatibility (EVC) processor support (1003212)
  
• Cannot add an ESX/ESXi host with running virtual machines to an EVC enabled Cluster (1009571)

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

1. Power off all the virtual machines in the ESXi cluster.
2. If needed, add the ESXi host to the vCenter Server inventory.
   
3. Click and drag the ESXi host with the older CPU into the cluster.
   
   Note: Though the EVC baseline is set for the ESXi host, you must place the ESXi host into the maintenance mode and power off the virtual machines. For more information, see EVC and CPU Compatibility FAQ (1005764).
   
   
4. Right-click the cluster and click Edit Settings.
5. Select VMware EVC and select Change EVC Mode.
6. From the VMware EVC Mode dropdown. select the appropriate EVC baseline for the oldest CPU.
7. All ESXi hosts should report Validation Successful, click OK.
8. If required, exit maintenance mode and power on virtual machines.

Additional Information

Enhanced vMotion Compatibility (EVC) processor support
EVC and CPU Compatibility FAQ
Cannot add an ESX/ESXi host with running virtual machines to an EVC enabled Cluster
How to enable EVC in vCenter Server
現在の EVC ベースラインよりも古い CPU を持つ ESXi ホストの追加
添加 CPU 低于当前 EVC 基准的 ESXi 主机