private void deleteFile(FileStatus file, HStore store, AtomicLong deletedFiles,
    AtomicLong failedDeletes) {
    Path filePath = file.getPath();
    LOG.debug("Removing {} from store", filePath);
    try {
      boolean success = store.getFileSystem().delete(filePath, false);
      if (!success) {
        failedDeletes.incrementAndGet();
        LOG.warn(
          "Attempted to delete:" + filePath + ", but couldn't. Attempt to delete on next pass.");
      } else {
        deletedFiles.incrementAndGet();
      }
    } catch (IOException e) {
      e = e instanceof RemoteException ? ((RemoteException) e).unwrapRemoteException() : e;
      LOG.warn("Error while deleting: " + filePath, e);
    }
  }
This Chore, every time it runs, will clear the unsused HFiles in the data folder.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/BrokenStoreFileCleaner.java