lib/sysrev/sysrev.js
function(user, systemId, cb) {
    writeTimeline(user, systemId, 'system unlinked', function() {
      // swallow any errors here
      _meta.unregister(user, systemId, function(err) {
        cb(err);
      });
    });
  }
function(user, systemId, cb) {
    writeTimeline(user, systemId, 'system unlinked', function() {
      // swallow any errors here
      _meta.unregister(user, systemId, function(err) {
        cb(err);
      });
    });
  }
unlink system from the daemon