Q: enable disk use on iPod classic

Putting iPod into Disk Mode - http://support.apple.com/kb/HT1363 - "When troubleshooting an issue with your iPod*, it's sometimes helpful to manually put it into Disk Mode. Learn how to manually put iPod into Disk Mode."

Copying Content from your iPod to your Computer - The Definitive Guide - http://www.ilounge.com/index.php/articles/comments/copying-music-from-ipod-to-co mputer/ - Information about use in disk mode pertains only to older model iPods.

To use your iPod as a storage drive. See here for more information.

Using your iPod as a storage drive

B-rock

Summarizing if you don't like to read Instructions and manual.

Sandy, if you dont want to put the iPod in Disk Mode, and use ity as a portable hardisk, but just asking about

the function or benefit of "Enable Disk use"

Normally if I want to add just a song or two from my library or playlist to iPod, I would put the iPod in

1. Manually Manage,
2. then ensure that enable disk use is tick
3. Drag the song/s from the library to the iPod icon or playlist.
   

So retaining all the songs in the iPod, this is much faster than Sync, and dont give problem like timeout and freezing iTunes.

Have a nice day!