[Plugin: W3 Total Cache] Update Media Library Export very Long after 76% done

Hi
Because I made two many change on a dev version of my website, I try to upload again all my Media Library. I just have around 197 files. I checked all the files (file name)
I try 4 times, but each time after 76% done, the Time elapsed increase till 9h without finish.
Have you an idea?
I run my Website on a VPS (http://www.gregoirenoyelle.com/)

http://wordpress.org/extend/plugins/w3-total-cache/