default FileSystem getFileSystem() {
    // This default is pretty dodgy!
    Configuration c = getConfiguration();
    FileSystem fs = null;
    try {
      if (c != null) {
        fs = FileSystem.get(c);
      }
    } catch (IOException e) {
      // If an exception, just return null
    }
    return fs;
  }
Returns Return the FileSystem object used (can return null!).
hbase-server/src/main/java/org/apache/hadoop/hbase/Server.java