dtSecretManager = createDelegationTokenSecretManager(conf);
this.nameNodeAddress = nn.getNameNodeAddress();
this.registerMBean(conf); // register the MBean for the FSNamesystemStutus
this.dir = new FSDirectory(this, conf);
StartupOption startOpt = NameNode.getStartupOption(conf);
this.dir.loadFSImage(getNamespaceDirs(conf),
getNamespaceEditsDirs(conf), startOpt);
long timeTakenToLoadFSImage = now() - systemStart;
LOG.info("Finished loading FSImage in " + timeTakenToLoadFSImage + " msecs");
NameNode.getNameNodeMetrics().fsImageLoadTime.set(