public void addVolumeCheck(long total, long free, long time) {
    stats.setLong(volumeSizeId, total);
    stats.setLong(volumeFreeSpaceId, free);
    stats.incLong(volumeFreeSpaceChecksId, 1);
    stats.incLong(volumeFreeSpaceTimeId, time);
  }
Returns the current value of the "diskSpace" stat.
geode-core/src/main/java/org/apache/geode/internal/cache/DiskDirectoryStats.java