When trying to create VM with memory smaller then 1 GB,
I get the following error:

Failed to create a compute v4 XXX (oVirt) instance lori-leupold.tlv.redhat.com: Fault reason is "Operation Failed". Fault detail is "[Cannot add VM. Physical Memory Guaranteed cannot exceed Memory Size.]". HTTP response code is 400.

This error happens because in Ovirt, the default value of memory guaranteed is 1 GB,
and that cause the memory to be smaller then the memory guaranteed.