Frequently Asked Questions

1 VirtualBox Shared Folders

1.1 Mount fails with ‘protocol error’

This usually means that your shared folder name is not configured correctly. The name I recommend (and require for the make script to work) is host.

1.2 Mount fails with ‘no such device’

This can happen if your host-guest integration (called VirtualBox Guest Additions) is no longer working. Perhaps you need to reinstall the Guest Additions (see below).

2 VirtualBox Guest Additions

The Guest Additions is a set of software, including kernel modules, installed on the guest that allows it to integrate with the host using shared folders, more convenient keyboard and mouse caputer, etc. My virtual machine came with guest additions working, but a software upgrade can interfere with them if the kernel is updated.

Fortunately, it's simple to reinstall. The VBox window should have a Devices menu, and under there select Install Guest Additions. You may have to dismiss a useless dialog, but you should see a CD appear on the Linux desktop. Open a terminal window and try: 

sudo /media/cdrom/VBoxLinuxAdditions-x86.run

Go through the prompts and it will reinstall for your current kernel. After that, restart the guest (using the "adminuser" menu on the right) and when it comes up try your mount command again. You shouldn't lose any of the other files you've checked out or anything.