Pixelmon Mod

Error occurred during initialization of VM
Could not reserve enough space for 2097152KB object heap
Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
This is what it said when I tried to put more gigabytes inside minecraft.Help me please

Either you don't have enough RAM on your system, or you are running other programs that are taking up your memory.