After looking at several deployments of VMWare, we had one deployment where the company enabled balloon mode which is essentially a way to overcommit memory the hostnode(s) don't have. Let's say you have put your database into memory or use a cached service in Apache or haproxy/nginx. VMWare will start taking some portions of these and at some point it corrupts things and the application running will either crash, malfunction or segfault.
Another factor is that OOMwill be........