There is a world in Terran space that the cyber families colonized shortly after Contact.  It was an inhospitable world, one where humanity did not live, orbiting a star that humanity does not travel to.  We built a repository of knowledge there, deep underground.  Every cyber that has ever lived, every cyber still alive, is there.  Everything we know is there.  This world is a total and complete backup of our entire race.  It is one of many.