Cold migration(xvMotion) across VMware vCenter Server fails during per-checks stage with error "A general system error occurred: vim.Datastore:datastore-XXX"

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:
Cold migration(xvMotion) across vCenter VMs fails during per-checks stage with error "A general system error occurred: vim.Datastore:datastore-XXX" Datastore-XXX in the error refers to the swap datastore ID.  Whenever, there is a swap datastore set at the host in the source VC. The reported error is not specific to relocate but it's a general error pertaining to all the X-VC operations like migrate/relocate/clone whenever there is a swap datastore set to the host where the source VM is residing.

Source vcenter vpxd.log:
2020-11-25T15:13:01.195Z info vpxd[62475] [Originator@6876 sub=Default opID=khuyyab2-161412-auto-3gjp-h5:70013261-6f] [VpxLRO] -- ERROR session[5241923b-####-####-####-########0c5]52e87633-####-####-####-########fc3 -- ProvChecker -- vim.vm.check.ProvisioningChecker.checkRelocate: vmodl.fault.SystemError:
--> Result:
--> (vmodl.fault.SystemError) {
-->    faultCause = (vmodl.MethodFault) null,
-->    faultMessage = (vmodl.LocalizableMessage) [
-->       (vmodl.LocalizableMessage) {
-->          key = "com.vmware.vim.vpxd.vmcheck.entityNotFound",
-->          arg = (vmodl.KeyAnyValue) [
-->             (vmodl.KeyAnyValue) {
-->                key = "arg",
-->                value = "vim.Datastore:datastore-XXX"
-->             }
-->          ],
-->          message = "vim.Datastore:datastore-XXX not found."
-->       }
-->    ],
-->    reason = ""
-->    msg = "A general system error occurred: "
--> }
--> Args:
-->
--> Arg vm:
--> 'vim.VirtualMachine:d8153630-####-####-####-########26a:vm-17889'
--> Arg spec:
--> (vim.vm.RelocateSpec) {

Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

Environment

VMware vCenter Server 7.0.x

Cause

The issue lies with the _hostconfig not getting updated properly with UUID in the case of LocalSwapDatastore, when the VPXD services are started on the source VC.

Resolution

This issue is resolved in VMware vCenter Server vCenter Server 7.0 Update 2c (build number 18356314)

Workaround:
Disconnect->reconnect the source host (OR) Restart vpxa service on the source host by running below command to resolve this issue.

# /etc/init.d/vpxa restart

Note: The error is not seen unless maybe when the vpxd is restarted again or restart of vCenter.