While the “automatic” installation didn’t work exactly as written, I mananged to make it work by hybriding the auto with the manual. Basically I made all the folders setting the permissions first, then I ran plug-in. The first time I tried to make it work, it blasted wordpress from working at all. I had to delete the cache plug-in, the folders, the symlink and start again. The second time it worked. Things are faster. Hurray.

Click to get wp-cache.