[Still-One]

Originally Posted by New to Mac

Is there a way to back up the internal MSxx drive to an external drive?

Yes. This is from pages 44-45 of the 750's manual.

MS750 Music Backup
It is possible to backup and restore the music contents of a MS750 using the CIFS or “Windows” Networking feature. Backup is accomplished by mounting the MS750 onto your PC or Mac desktop and using your computer’s backup software.
You can also backup the music files to any standard media which your PC supports, such as: DVD+/-R, DVD+/-RW, CD-R, CD-RW, or external hard drive.
There are several methods and tools for backing up your MS750’s music content. You will have to determine which method is best for you. One such method involves attaching an external FireWire or USB hard drive to your PC and backing up your Content directory by using a simple drag and drop from the Content directory to the external drive or using more elaborate features provided by a third party backup software product such as Dantz Retro- spect. A free trial of this software is provided by Dantz for both Mac and Windows users. Please visit the Dantz web site for more details: Retrospect personal.dtml
Only the music files are available in the Content folder. Play Lists are available in the Play Lists folder. Setup infor- mation, and Internet Ra- dio stations are NOT available for backup at this time.
44
A full 500 GB backup could take 2.5 days to complete using a standard 10/100 baseT Ethernet network. It is not recommended that you use your MS750 to play music while a backup is in progress as this will cause the backup to take longer to complete.
Note: A good place to start is the PC and MAC Integration documents that can be found on the McIntosh Web Site at McIntosh Analytical Systems.