There are times where a virtual machine migration option might be greyed out due to several reasons, including vMotion License or backup tasks that have just recently completed but the relatives entries have not yet been removed from vCenter’s database tables.
Fortunately, VMWARE has provided administrators a manual way to remove such entries in order to re-enable migration options, in just 3 simple steps:
Identify VM’s MOB ID: What is a MOB ID? In simple words, it would be a unique internal identifier that is generated by vSphere when new objects are created in vCenter. To easily find that unique ID, select a VM and find the vm-xxxx on your browser’s URL.
As of the above example, this number in red color, would be the MOB ID of the selected VM in my lab.
Use this URL, editing to reflect your vCenter’s netbios name or IP Address where appropriate and validate with admin credentials:
VMWARE suggests to use the .local admin account, yet any account with administrative access will work just fine.
You will be granted access to this page as of the below screenshot.
Then, on first box (entity), replace the Object’s reference (MOID) with the appropriate one; Afterwards, go to the second box (method) and set RelocateVM_Task as value.
To commence the request, you will need to click on Invoke Method, on the right of the table.
You should now be able to migrate your VM!