vMotion failed with the error 'AH related spec cannot be applied to proposed config.'

Products

• VMware vCenter Server

Issue/Introduction

When attempting to perform a live vMotion of a virtual machine from one ESXi host to another, the operation fails with the error 'AH related spec cannot be applied to proposed config'. This indicates that the target host does not support the same advanced hardware features required by the virtual machine.

Corresponding messages can be found by inspecting /var/log/vmware/vpxd/vpxd.log on the vCenter Server:

YYYY-MM-DDTHH:MM:SS.019Z warning vpxd[######] [Originator@6876 sub=Vmomi opID=lzhckuuu-#######-auto-yyyyy-h5:] VMOMI activation LRO failed; <<########-####-####-######, <TCP '127.0.0.1 : 8085'>, <TCP '127.0.0.1 : 37432'>>, vm-####, vim.VirtualMachine.relocate, <vim.version.v8_0_3_0, internal, 8.0.3.0>, (null)>, N3Vim5Fault12InvalidState9ExceptionE(Fault cause: vim.fault.InvalidState
--> )

--> (vim.fault.InvalidState) {
-->    faultCause = (vmodl.MethodFault) null, 
-->    faultMessage = (vmodl.LocalizableMessage) [
-->       (vmodl.LocalizableMessage) {
-->          key = "AH related spec cannot be applied to proposed config.", 
-->          arg = <unset>, 
-->          message = <unset>
-->       }
-->    ]
-->    msg = ""
--> }

YYYY-MM-DDTHH:MM:SS.019Z warning vpxd[######] [Originator@6876 sub=drmLogger opID=CdrsLoadBalancer-#####] VM [vim.VirtualMachine:vm-####,VM_name]: On-host overheadLimit (263) is larger than the DRS-generated value (259).

Environment

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

vCenter Server 7.x

vCenter Server 8.x

Cause

The virtual machine is in an invalid state due to an issue with the overhead stats in the config cache.

Resolution

1. Ensure the virtual machine is powered off to avoid data loss during the process.

2. Set Distributed Resource Scheduler (DRS) to manual to prevent automatic rebalancing from interfering with the re-registration process. 

3. Un-register the virtual machine from its current host by right-clicking the virtual machine in vCenter and selecting "Remove from Inventory"

4. Navigate to the datastore where the virtual machine files are located and re-register the virtual machine on a different host that meets the required hardware specifications.

5. Switch the DRS mode back to "Automatic".

6. Power on the virtual machine back after successful re-registration.

7. Attempt vMotion again.