VMs created by the MTV tool have both "spec.template.spec.memory.guest" AND "spec.template.spec.resources.requests.memory" defined in the VM definition. When using the UI to change the Memory only "spec.template.spec.memory.guest" is modified, and "spec.template.spec.resources.requests.memory" remains untouched. This can cause multiple scheduling issues including not being able to schedule VMs (when "spec.template.spec.memory.guest" is lower than "spec.template.spec.resources.requests.memory")

MTV operator 2.7.5, OCPV 4.17.1
This has only been tested with the above versions, but probably effects other versions

Every time, when modifying VMs created by MTV operator 2.7.5.

1. Migrate a VM from vSphere
2. Using the OCP-V UI, decrease the memory assigned to the VM
3. Check the YAML to see that "spec.template.spec.memory.guest" does not match "spec.template.spec.resources.requests.memory" 

"spec.template.spec.memory.guest" does not match "spec.template.spec.resources.requests.memory"

"spec.template.spec.memory.guest" match "spec.template.spec.resources.requests.memory"

It is not clear to me if MTV should not be adding the "spec.template.spec.resources.requests.memory" to the YAML, or if the OpenShift Virt UI should be ensuring that both entries are updated.