The safe way to upgrade your file server is simply to update the kernel binaries (for example, with the ones I'm providing) on your 9fat and reboot.
Then, you can pull the updated program binaries from /n/sources. There is no need to wait, because you have to be running the new kernel before pulling the new binaires anyway. In the case you need a custom kernel to boot your file server, you will have to grab the changes manually (like http://9fans.eu/pegasus/sources/plan9/plan9-2014-05-15.diff), and recompile/reinstall/reboot your kernel. -- David du Colombier