I have a new 8 core machine with 16GB of RAM. I want to run VMs on it using Ubuntu and KVM. Nothing else but SSH will be running on the host.
My question is what is the maximum amount of cores and of RAM which I can use for the VMs. Can I create 4 VMs and assign 2 cores and 4GB RAM each? Will the host OS have problems with such setup?
Stated in other way, what is the minimum amount of cores and RAM which is needed for the host to run the VMs? Will 1 core and 1GB of RAM be enough to run the VMs.
Best Answer
there is no maximum as such, same as there is no real maximum for memory. You need to keep in mind the following:
As for the RAM allocation, this is basically the same line of thought:
So, having said that, you need to consider what your VMs will absolutely require (don't just give a VM 4 cores because you can, give it the minimum it needs to run, and add more later if you see performance issues).
Be careful with memory allocation - you never want to end up in swap.