During my weekly VMware training sessions, I’m always getting a bit excited when we reach the module where the ESX and virtual machine memory is covered. I’m trying to explain how important it is; not to use the virtual machine memory limit setting and very often students believe me after checking out their own production environment for ballooning activity and 9 out of 10 times they find a few virtual machine which have a memory limit configured. The memory limit is the upper limit on memory the ESX host makes available to virtual machine.