I'm currently running Ubuntu 13.04, and I've got a Windows 8 VirtualBox VM installed. I put the VM's folder in a shared folder (/home/sharedHome/) that has read and write permissions assigned to the vboxusers group. This allows me to launch the VM from my account and my wife can launch it from hers.
The only problem is that when you launch the VM from either account, the permissions get changed so that only that user has read and write privileges on the .vbox file. After this happens, the other account can't launch the VM unless I go in and change the permissions again.
Does anyone know how to prevent VirtualBox from changing the permissions? Is there a better way to share a VM between users?