How to enable shared folders on VirtualBox CentOS guest

1. Add shared folders for the virtual machine in Settings -> Shared Folders, select Auto-mount option.
2. Start your virtual machine, the shared folders should be mounted in /media section with sf_prefix.
To make them accessable for a non-root user add this user to vboxsf groupe

sudo usermod -a -G vboxsf username


- replace username here with the actual user name;
- restart the guest, and the shared folders should be available.

Here is another method.