问如何增加流浪者创建的虚拟机的磁盘空间

EN

 Vagrant.configure("2") do |config|
  (2..4).each do |i|
    config.vm.define "node#{i}" do |node|
      node.vm.provider "virtualbox" do |v|
        v.name = "node#{i}"
        v.memory = 3072
        v.cpus = 2
        config.disksize.size = '20GB'
      end
      node.vm.box = "cnode"
      node.vm.hostname = "node#{i}"
      node.vm.network :private_network, ip: "192.168.3.#{i}"
    end
  end
end

[vagrant@node2 opt]$ df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root  8.4G  1.1G  7.4G  13% /
devtmpfs                 1.4G     0  1.4G   0% /dev
tmpfs                    1.4G     0  1.4G   0% /dev/shm
tmpfs                    1.4G  8.3M  1.4G   1% /run
tmpfs                    1.4G     0  1.4G   0% /sys/fs/cgroup
/dev/sda1                497M  118M  379M  24% /boot
none                     234G  148G   87G  64% /vagrant