How can I create a VM in Vagrant with VirtualBox with two CPUs?

On Windows 7 64 bit trying to start up a VM (Ubuntu 32 bit). I'm having trouble getting my VM to show two cores despite adding the modify vm command in my Vagrantfile. My Vagrant version is 1.2.2.

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant.configure("2") do |config|
  config.vm.box = "precise32"
  config.vm.box_url = "http://files.vagrantup.com/precise32.box"
  
  config.vm.provider :virtualbox do |vb|
    vb.customize ["modifyvm", :id, "--memory", "2048"]
	vb.customize ["modifyvm", :id, "--cpus", "2"]	
  end  
end

With this Vagrantfile I issue the vagrant up command. Then I issue vagrant ssh followed by lscpu which yields:

Architecture:          i686
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                1
On-line CPU(s) list:   0
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 58
Stepping:              9
CPU MHz:               2565.513
BogoMIPS:              5131.02
L1d cache:             32K
L1d cache:             32K
L2d cache:             6144K

I think CPU(s) should show 2, so my VM only has one CPU right now. How can I get 2 CPUs to show up when I run lscpu?

Add vb.customize ["modifyvm", :id, "--ioapic", "on"] to the config.vm.provider block inside your Vagrantfile.

Looking at the VirtualBox documentation it mentions:

> "Note Enabling the I/O APIC is required for 64-bit guest operating > systems, especially Windows Vista; it is also required if you want to > use more than one virtual CPU in a virtual machine."

If you are running vagrant using Oracle Virtualbox then the most common issue is with Hyper-V in Windows 7, 8 or 10. That will limit you to 32bit and one cpu.

Run or search for "Windows Features" and select "Turn Windows Features On or Off".

In the checkboxes make sure Hyper-V is off - you can't enable VT-x for Virtualbox with Microsoft Hyper-V hogging it.

Then, you can make your Vagrantfile boot very user friendly with:

  config.vm.provider "virtualbox" do |vb|
    vb.memory = "2404"
    vb.cpus = "2"
  end

Assuming you want to have two cores running and just a bit over 2 Gig of memory

ps - don't forget to add your port forwarding. For PHPStorm (xdebug, mysql, and web) I use:

  config.vm.network "forwarded_port", guest: 80, host: 8080
  config.vm.network "forwarded_port", guest: 3306, host: 3306
  config.vm.network "forwarded_port", guest: 9000, host: 9000

It seems you have not mentioned which provider you are using. As of Vagrant 1.7 many VM providers (such as VirtualBox, HyperV) supports the following configuration in your Vagrantfile:

config.vm.provider "virtualbox" do |v|
  v.memory = 1024
  v.cpus = 2
end

Check out the specific provider you are using in the vagrant documentation.