public static void checkCritical(float val) {
    if (val < 0 || val > 100) {
      throw new IllegalArgumentException(
          String.format(
              "Disk usage critical percentage must be set to a value between 0-100.  The value %s is invalid.",
              val));
    }
  }
Validates the critical percent.

@param val the value to check
geode-core/src/main/java/org/apache/geode/internal/cache/DiskStoreMonitor.java