@nengelhardt Export your images and host list, build up a new Fedora 22 server build, install FOG trunk, and import your hosts and images, then recreate your “image definitions”. Then set your DHCP option 066 to reflect the (possibly) new IP address.
The easiest way to accomplish this is to run in parallel for a little while. Although many people don’t just have spare servers or powerful desktops laying around to dedicate to a new FOG server… But if you did, it’d be as easy as mounting the remote NFS share on the new FOG server to a temporary directory, and then copying over your images. The host export bit is just done in the web interface under Host Management. You may not even need or want to do this if you have only a few machines registered.
If you don’t have spare hardware laying around, you’ll need to connect to a remote windows share and just copy your images there (recursively). You would then later connect to that share via Fedora 22 Server and copy them back (CLI recursively).
Here is an article on the various ways to move to FOG Trunk. You don’t need any pre-existing version of fog to install FOG trunk… The article name is deceiving but it was written for the needs of the many (upgrading). https://wiki.fogproject.org/wiki/index.php/Upgrade_to_trunk