How would one go about to upgrade from the release version of freenas 8 to the beta 4? It says something in the notes that you can't upgrade from previous versions than beta 3. Is the way to do this to upgrade first to beta 3 and then to beta 4?
Read the Release Notes a bit closer. You can upgrade from earlier 8 versions, but only from CD (i.e. not from the GUI). The other option is to save the config, reinstall the new version, then restore the config. A fuller description is at http://doc.freenas.org/index.php/Upgrading_FreeNAS.
I was just very conscious of losing my data and didn't dare do anything before I heard from an actual person. Thank you for your reply, I will read it thourugly. :)
Most importantly, if your install device is smaller than 2GB, you can't upgrade directly to 8.01 Beta 3 or later, and will need to take an indirect upgrade path.