Other Mount Options
When you are mounting an existing member of a volume set that was created using more than one piece of storage media (multiple surfaces on multiple media), the following screen will be displayed:
This allows you mount the additional members of a volume set so that the complete set may be accessible if needed. Select the Ok button.
Note: If you do not desire to continue with the mounting of the volume set at this point, select the Eject Members option, and the member will be ejected to the mail-slot of the library.