In some cases, even if the « Hot Add » option is enable, it’s not possible to add memory to a powered on VM.
The following conditions prevent to increase the memory to more than 3Gb:
- If the powered-on virtual machine has less than 3GB of memory, you cannot hot add memory in excess of 3GB.
- If the virtual machine has 1GB of memory, you can add 2GB.
- If the virtual machine has 2GB of memory, you can add 1GB.
- If the virtual machine has 3444MB of memory, you can add 128MB.
- If the powered-on virtual machine has exactly 3GB memory, you cannot hot add any memory.
In these cases, the only way to increase memory is to shutdown the VM, increase the memory to the required value, and restart the VM.