The next version of ESX vSphere or ESX 4 new features – Memory “Hot Add” for virtual machine is not a secret anymore. The most important is Microsoft announced the drop of hot-add support from its roadmap, postponed to an unannounced date, reported by Virtualization.Info which is totally not make sense and it’s confirmed worked on next version of ESX/vCenter.

I would like to share how to configure memory “hot add” for Windows 2003 virtual machine.

Memory hot add

Please make sure the virtual machine is power off before proceed and this is one time setup.

  • Right click on virtual machine
  • Click Edit Settings
  • Click Options
  • Select “Enable memory hot add for this virtual machine” under Memory/CPU Hotplug.
  • Click OK

ESX 4 Memory Hot Add

Testing time! Power on your virtual machine and increase your memory size on the fly now.

Note: You can increase the memory on the fly but NOT decrease the memory during virtual machine is power on.