Virtual CD/DVD drives by default support only reading. The medium configuration is changeable at runtime. You can select between the following options to provide the medium data:
Host Drive defines that the guest can read from the medium in the host drive.
Image file gives the guest read-only access to the data in the image. This is typically an ISO file.
Empty means a drive without an inserted medium.
Changing between the above, or changing a medium in the host drive that is accessed by a machine, or changing an image file will signal a medium change to the guest OS. The guest OS can then react to the change, for example by starting an installation program.
Medium changes can be prevented by the guest, and Oracle VM VirtualBox reflects that by locking the host drive if appropriate. You can force a medium removal in such situations by using the VirtualBox Manager or the VBoxManage command line tool. Effectively this is the equivalent of the emergency eject which many CD/DVD drives provide, with all associated side effects. The guest OS can issue error messages, just like on real hardware, and guest applications may misbehave. Use this with caution.
The identification string of the drive provided to the guest, displayed by configuration tools such as the Windows Device Manager, is always VBOX CD-ROM, irrespective of the current configuration of the virtual drive. This is to prevent hardware detection from being triggered in the guest OS every time the configuration is changed.
The standard CD/DVD emulation enables reading of standard data CD and DVD formats only. As an experimental feature, for additional capabilities, it is possible to give the guest direct access to the CD/DVD host drive by enabling passthrough mode. Depending on the host hardware, this may potentially enable the following things to work:
CD/DVD writing from within the guest, if the host DVD drive is a CD/DVD writer
Playing audio CDs
Playing encrypted DVDs
There is a Passthrough check box
in the VirtualBox Manager dialog for configuring the media
attached to a storage controller, or you can use the
--passthrough option with VBoxManage
storageattach. See
Section 7.17, “VBoxManage storageattach”.
Even if passthrough is enabled, unsafe commands, such as updating the drive firmware, will be blocked. Video CD formats are never supported, not even in passthrough mode, and cannot be played from a virtual machine.
On Oracle Solaris hosts, passthrough requires running Oracle VM VirtualBox with real root permissions due to security measures enforced by the host.