[HADOOP-4826] Admin command saveNamespace.

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.20.0
• Hadoop Flags: Incompatible change, Reviewed
• Release Note: Introduced new dfsadmin command saveNamespace to command the name service to do an immediate save of the file system image.
• Assignee: Konstantin Shvachko
• Reporter: Konstantin Shvachko
• Created: 10/Dec/08 20:42
• Updated: 30/Nov/10 18:56
• Resolved: 12/Dec/08 22:06

Description

It would be useful to have an admin command that saves current namespace.
This command can be used before regular (planned) cluster shutdown.
The command will save the namespace into storage directory(s) and reset the name-node journal (edits file).
It will also reduce name-node startup time, because edits do not need to be digest.

Issue Links

• relates to: HDFS-352 saveNamespace command should be documented.
• relates to: HDFS-1508 Ability to do savenamespace without being in safemode