CDH4's ZooKeeper Failover Controller (ZKFC) has been installed.
Starting the ZKFC service:
[vagrant@localhost ~]$ sudo service hadoop-hdfs-zkfc start                      
Starting Hadoop zkfc:                                      [  OK  ]
starting zkfc, logging to /var/log/hadoop-hdfs/hadoop-hdfs-zkfc-localhost.localdomain.out
does not seem to work as the log file is empty:
sudo vim  /var/log/hadoop-hdfs/hadoop-hdfs-zkfc-localhost.localdomain.log
Question
How to run HDFS' ZKFC?
 
    