@Override
  public void killRegionServer(ServerName serverName) throws IOException {
    HRegionServer server = getRegionServer(getRegionServerIndex(serverName));
    if (server instanceof MiniHBaseClusterRegionServer) {
      LOG.info("Killing " + server.toString());
      ((MiniHBaseClusterRegionServer) server).kill();
    } else {
      abortRegionServer(getRegionServerIndex(serverName));
    }
  }
Alternate shutdown hook. Just shuts down the passed fs, not all as default filesystem hook
does.
hbase-testing-util/src/main/java/org/apache/hadoop/hbase/MiniHBaseCluster.java