How do I increase the RAM and set up host-only networking in Vagrant?

To increase the memory or CPU count when using Vagrant 2, add this to your Vagrantfile

Vagrant.configure("2") do |config|
    # usual vagrant config here

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

Since Vagrant 1.1 customize option is getting VirtualBox-specific.

The modern way to do it is:

config.vm.provider :virtualbox do |vb|
  vb.customize ["modifyvm", :id, "--memory", "256"]
end

You can modify various VM properties by adding the following configuration (see the Vagrant docs for a bit more info):

  # Configure VM Ram usage
  config.vm.customize [
                        "modifyvm", :id,
                        "--name", "Test_Environment",
                        "--memory", "1024"
                      ]

You can obtain the properties that you want to change from the documents for VirtualBox command-line options:

• http://www.virtualbox.org/manual/ch08.html#vboxmanage-modifyvm

The vagrant documentation has the section on how to change IP address:

Vagrant::Config.run do |config|
  config.vm.network :hostonly, "192.168.50.4"
end

Also you can restructure the configuration like this, ending is do with end without nesting it. This is simpler.

config.vm.define :web do |web_config|
    web_config.vm.box = "lucid32"
    web_config.vm.forward_port 80, 8080
end
web_config.vm.provision :puppet do |puppet|
    puppet.manifests_path = "manifests"
    puppet.manifest_file = "lucid32.pp"
end