private long startAsyncWrite(DiskRegion dr) {
    if (stoppingFlusher) {
      if (isClosed()) {
        throw (new Stopper()).generateCancelledException(null); // fix for bug
                                                                // 41141
      } else {
        throw new DiskAccessException(
            "The disk store is still open, but flusher is stopped, probably no space left on device",
            this);
      }
    } else {
      pendingAsyncEnqueue.incrementAndGet();
    }
    dr.getStats().startWrite();
    return getStats().startWrite();
  }
Get serialized form of data off the disk

@since GemFire 5.7
geode-core/src/main/java/org/apache/geode/internal/cache/DiskStoreImpl.java