EVC blocking migration

[oussama omrani]

Hello,

I got this error when i tried to migrate a running VM from a new host to an old one (like downgrade).

The target host does not support the virtual machine’s current hardware requirements. To resolve CPU incompatibilities, use a cluster with Enhanced vMotion Compatibility (EVC) enabled. See KB article 1003212. 

I Cannot power off the vms due to critical production Use. How can i fix this issue? The Vmware is Vsphere 8 and hosts are ESXi 8

[snapfriend]

Hello 

There are only 2 workaround for this issue as mentioned below & it is required downtime of VMs. It is not possible with Live Migration (vMotion) option.

Workaround:

To work around the The target host does not support the virtual machine’s current hardware requirements error when EVC cannot be enabled, perform a powered-off cold migration of the virtual machine.

Or

Power off the virtual machine to configure an EVC mode supported by both the source and target hosts; then, power it back on to perform a live migration. (Refer to Configure the EVC Mode of a Virtual Machine)

This issue occurred due to with below cause

Cause

• vMotion requires the same family of CPU among the ESXi hosts which ensures the same CPU feature set to be presented to all virtual machines. 

• Any vSphere cluster can have hosts belonging to either Intel or AMD.

• EVC cannot be enabled on a cluster with mixed processors from both Intel and AMD. For vMotion to work, it needs compatibility in terms of host processors in the cluster.

• vMotion will fail if the source ESXi host CPU features are not supported on the destination ESXi host.

Note: vMotion requires the source and destination ESXi hosts to present the same CPU generation feature set.

Please find below reference article from VMware & it explains in detailed about Enable Enhanced vMotion Compatibility (EVC)

ERROR: The target host does not support the virtual machine’s current hardware requirements.

[Charlie Silverman]

To add to snapfriend's answer, provided that both clusters are the same family of processor (Intel or AMD), what I would recommend is trying to set EVC mode on the old cluster and find the highest EVC mode you can set that supports your current processors.  If there are no compatibility issues with your hosts, you may be able to enable EVC mode on the existing cluster without requiring the VMs to be powered down as long as the EVC mode you select directly matches the processors in that cluster.

If you can make that work, just enable the same EVC mode on the new cluster.  At that point, you may be able to successfully vMotion the VMs to the new cluster.

As with most things, your mileage may vary, but I have successfully done this exact migration before, with the above noted caveats.