I have a laptop with a core2duo CPU. When I am setting up my Ubuntu VM, should I set it to have 2 cores or 1? Do you always set it to the number of cores your host has?
tl;dr: It doesn't matter, so use one core.
Full version: If you're talking about the number of cores the virtual machine has, the number of cores the host has doesn't really matter, with some important caveats"
Unless you have a reason to set the VM to multiple cores, set it to 1.