Hi,
The way we utilize Virtual machine related alerts is to use them on Resource Pool level,
For example: we have "Development:", "Production Normal" and "Production Critical" pools,
Development does not have alerts assigned, it helps us to avoid alerts during P2V processes and such when we specify "Development" resource pool as a destination.
I am sure if you specify more details on your environment, patch level and what is your VC looks like (RAM, CPU), it will help us to come with other valid solutions,
HTH,
Alex