static double parseDiskSpacePercentage(S s) {
  L<S> l = regexpGroups("(\\d+) MB free of (\\d+) MB\\.", s);
  if (empty(l)) ret -1;
  double ratio = 1-doubleRatio(parseInt(first(l)), parseInt(second(l)));
  l = regexpGroups("Free inodes: (\\d+)K/(\\d+)K", s);
  if (nempty(l)) { 
    double ratio2 = 1-doubleRatio(parseInt(first(l)), parseInt(second(l)));
    print("ratio=" + ratio + ", ratio2=" + ratio2);
    ratio = max(ratio, ratio2);
  }
  ret ratio*100;
}