Symlink Piwik - Which folders and files?

Hi all!

Im trying to symlink piwik to host multiple instances with one source. Does someone knows which folders and files should be get symlinks?

I would symlink all files and folders at root-dir of piwik without config/ and tmp/

Is that the right way? Do i need to exclude some more folders or direcroties? Do i must symlink the tmp/-Folder and all files in the config/-Folder?

Background: I like to host multiple instances for diiferent customers - but all should use the same version and the same plugins.

Many thanks for your answers!