If you want live backup, granular backup / restore and deduplication features, try BackupChain.
Especially if you are dealing with larger VMs it's far more efficient to use a specialized backup tool; however, for tiny VMs I guess you can do as WoodyZ recommends and shut down the VM without losing much time. It's also important to have VMware tools installed and always up-to-date if you choose the live backup option
Hope this helps!