new format for -format command is:
namenode -format -clusterid cid
hdfs user guide needs to be updated.
HDFS scalability with multiple namenodes
The documentation here: https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/HDFSCommands.html contains the correct details. Should we close this ticket?
Yes, we should close this ticket. Thanks Manjunath Ballur!
The issue has been fixed.