If a drive letter or mount point is not specified, or is in use already, an alternative location is found by the Guest Additions service. The service searches for an alternative location depending on the guest OS, as follows:
Windows and OS/2 guests.
Search for a free drive letter, starting at
Linux and Oracle Solaris
guests. Folders are mounted under the
For example, if you have a shared folder called
The guest properties
Access to an automatically mounted shared folder is granted to
everyone in a Windows guest, including the guest user. For Linux
and Oracle Solaris guests, access is restricted to members of
the group