iPod Defragged ipod - everything gone

After two years of use I finally decided to defrag my 160 GB ipod classic.

In iTunes, I enabled disk use. Then I used TechTool Pro 5 to:
Run a Surface Scan and Volume Structures Scan - No errors.
Run File Optimization followed by Volume Optimization.

Upon completion of the last 2 (defragging) the ipod reads as empty-no files.

Anyone know what I did wrong?

Can I quickly fix it or do I have to do an ipod restore under iTunes and just reload my library?

Thanks

I guess I didn't realize that. I was trying to improve the ipod's performance. There are all kinds of articles on the web about defragging your ipod:

http://www.wikihow.com/Defragment-an-iPod

OK then, restore and resync it instead.