Apple Final Cut Pro 7 - Manual (Page 361)

When you’re ingesting spanned clips using the Automatic Transfer feature, it’s
recommended that you mount all the volumes that hold the different segments of a
spanned clip so that Final Cut Pro has access to the volumes it needs before you turn on
automatic transfer. If not all volumes are mounted, Final Cut Pro transfers as many
segments of the spanned clip as are available on the mounted volumes as individual
clips. You can later mount the missing volumes, complete the transfer of the missing
segments of the spanned clip, and then reassemble the spanned clip. For more information
about spanned clips, see
“Viewing Spanned Clips in the Browse Area.”
361 Chapter 24 Transferring File-Based Media