I recently got a Synology DS918+ NAS. I would like to replace the built in OS (DSM?) with just stock Debian (or Ubuntu). Is this possible? How can I do it. I've installed lots ofd Ubuntu/Debian servers and desktops, I've set up dozens of RAIDs, accessing this through a SSH terminal is my natural habitat. However, I cannot see how to boot from the Debian netinstall USB stick I have.