[HDFS-4508] Two minor improvements to the QJM Deployment docs

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 2.0.3-alpha
• Component/s: documentation
• Assignee: Daisuke Kobayashi
• Reporter: Harsh J
• Created: 17/Feb/13 13:23
• Updated: 21/Feb/13 13:47

Description

Suggested by ML user Azurry, the docs at http://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/HDFSHighAvailabilityWithQJM.html#Deployment_details can be improved for two specific lines:

• If you have already formatted the NameNode, or are converting a non-HA-enabled cluster to be HA-enabled, you should now copy over the contents of your NameNode metadata directories to the other, unformatted NameNode by running the command "hdfs namenode -bootstrapStandby" on the unformatted NameNode. Running this command will also ensure that the JournalNodes (as configured by dfs.namenode.shared.edits.dir) contain sufficient edits transactions to be able to start both NameNodes.
• If you are converting a non-HA NameNode to be HA, you should run the command "hdfs -initializeSharedEdits", which will initialize the JournalNodes with the edits data from the local NameNode edits directories.