Virtualbox Guest Shared Folders

[DeepThought]

Code:

sudo adduser $USER vboxsf

I'm assuming by the above command you're trying to add yourself to vboxsf group.

The command to add a user to another group is actually, "sudo usermod -a -G <group> <user>".
So in your case try:

Code:

sudo usermod -a -G vboxsf $USER

You will need to logout/reboot the guest for this to take affect.

If you type "id" into the terminal it will list all the groups you belong to, a good way to check which groups you are a member of

Hope this helps.