vagrant up 报错 RawFile#0 failed to create the raw output file

config.vm.provider "virtualbox" do |vb|
 #   # Display the VirtualBox GUI when booting the machine
 #   vb.gui = true
 #
 #   # Customize the amount of memory on the VM:
     vb.memory = "4096"
     vb.cpus = "2"
     vb.name = "ubuntu_192.168.56.2"
     vb.customize [ "modifyvm", :id, "--uartmode1", "disconnected" ]
 end