Fails to start after running for a few months

I’m using the snappy image on a Rpi2 and it was working great but then i noticed it was down and it seemed that the SD card was ok but just refused to boot for some reason, popped the SDcard into my ubuntu server and the volumes look ok but it refuses to start. Is there anyway to re-image the sdcard and get it to pickup the data that is already on the sata disk?