Can't migrate VM from Host 1 and 5 to another hosts or vice versa

[rebelfalls]

My issue is I am not able to migrate the VM from Host 1 to another hosts (except host 5) and not able to migrate the VM from Host 5 to another hosts (except host 1)

In total I have  6 VMs on the host 1, that get the following error: "The target host does not support the virtual machine's current hardware requirements. Use a cluster with Enhanced vMotion Compatibility (EVC) enabled to create a uniform set of CPU features across the cluster, or use per-VM EVC for a consistent set of CPU features for a virtual machine and allow the virtual machine to be moved to a host capable of supporting that set of CPU features. See KB article 1003212 for cluster EVC information"

I can cold migrate the VMs from host 1 to host 3 and it works works. Then I power on the same host 3, then migrate it back to host 1 or any other host which works perfectly. I have several running machines and to perform the shutdown/ migrate/ power on task is very tedious.

EVC is enabled both at the cluster and VM level. I can’t disable/enable the EVC on the cluster as it does have many production VMs running on the cluster.

However as a workaround, I have

1. Power off VMs on Host1 ,5.
2. Migrate and Power on VMs on the Host 2,3,4,6.
3. vMotion back to Host 1 and 5. And now all VMs are able to migrate from Host 1 and 5.

But I am sure about what was causing the EVC error.

VMware vCenter Server Appliance 6.7.0.43000 with an external Platform Services Controller

VMware ESXi 6.5.0 build-10884925 Update 2 6- node cluster

[scott28tt]

What CPUs do you have in each of your 6 hosts?

What is your EVC level set to at the cluster level?

[nachogonzalez]

Hi, hope you are doing fine

Are all hosts the same in the cluster?
Do they fave the same CPU faimily?
Can you share CPU details?

What is the EVC level that you have enabled?
Do you have per vm evc enabled?

[ZibiM · Accepted solution]

Your issue is caused by the fact that vmotion check detects that CPU on the hosts 1 and 5 differs from the CPUs on the other hosts you have.

From your description it looks like it consider CPUs on host 1 and 5 as newer than the ones on the other hosts.

This might be caused by the CPU microcode firmware updates - especially the ones related to the Spectre and Meltdown mitigation patching.

Please check whether your hosts have the same firmware level

There might be also some BIOS settings that can cause EVC disparities - for example MWAIT