public void addDiskStore(DiskStoreImpl ds) {
    if (logger.isTraceEnabled(LogMarker.DISK_STORE_MONITOR_VERBOSE)) {
      logger.trace(LogMarker.DISK_STORE_MONITOR_VERBOSE, "Now monitoring disk store {}",
          ds.getName());
    }

    Set<DirectoryHolderUsage> du = new HashSet<>();
    for (DirectoryHolder dir : ds.getDirectoryHolders()) {
      du.add(new DirectoryHolderUsage(ds, dir));
    }
    disks.put(ds, du);
  }
Validates the critical percent.

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