VirtualBox: mounting shared folder fails during start-up, but succeed from shell

Question

Problem description:

When I boot my VirtualBox Guest OS, the mounting of the shared file-system - which is referenced in /etc/fstab - fails.
However, after login - mount -a succeeds.

Details:

The boot process gets stuck here ...

... and pressing s continues the boot process, which finishes.

In the shell, I verify that my shared directory is not mounted:

But now, from the shell, the mount of the shared file-system succeeds:

What should I do to make my mount succeed during start-up?

Environment:

• VirtualBox: 4.3.12.r93733
• Host OS: Windows 7
• Guest OS: Linux ubuntu 3.13.0-32-generic #57~precise1-Ubuntu x86_64 GNU/Linux
• /etc/fstab

• Relevant lines in /var/log/boot.log

Answer 1

You don't have to mount it, VitrualBox will make it for you. For me,these steps worked on my System (VirtualBox 5.0.10 on Windows 7 and Kubuntu 14.04 guest system):

• In VirtualBox, configure your shared folder for your machine under 'Shared Folder'. Pick up the directory on your host system (e.g. D:\shared) and set a name for your guest system (e.g. shared).

  • Boot the guest system. Now you should have a mounted folder under \media\sf_shared.

Thats all. VirtualBox manages this for you.

Answer 2

You need to install VirtualBox Guest Additions properly and use VirtualBox Manager to specify share folders. The issue happens because the mount point is in place with root permissions. The default mount location is in /media/sf_.

You can change mount point with VBoxControl command. To change the mount point from /media/sf_... to /home/user/sf_... use the command:

sudo VBoxControl guestproperty set /VirtualBox/GuestAdd/SharedFolders/MountDir /home/user/

To check if that's working:

sudo VBoxControl guestproperty get /VirtualBox/GuestAdd/SharedFolders/MountDir