routing - Using custom data in OSRM

I have my own routing server that uses OSRM as an routing engine. (I used this toturial.)

I want to be able to add my own data (roads) and include that data in the routing.

So in the beginning I thought to add my data in the OSM format (node, way, relation) with an id that doesn't exist in the xml file to the osm.xml file that the OSRM uses to route. But that will mess up the id's coming from the OSM server in case of updating the data (diff).

So now I'm wordering if there is any way to use OSRM with my own data.