CODEWITHSUNDEEP
hadoophdfsnamenode
earl
earl

Reputation: 768

Query on hadoop namenode -format command

While doing "hadoop namenode -format", below message comes.

Re-format filesystem in Storage Directory /opt/data/temp/dfs/name ? (Y or N)

What should one give here? "Y" or "N".

If given Y, will it lose data from HDFS?

Upvotes: 5

Views: 6309

Answers (1)

franklinsijo
franklinsijo

Reputation: 18270

This question will be prompted only when the dfs.namenode.name.dir already exists i.e., the directory is either formatted already or an existing directory is mapped to dfs.namenode.name.dir.

If you wish to Re-format it again, then give Y else N.

On giving Y, the directory will be formatted, deleting all the existing metadata (fsimage and edits logs). This re-format removes only the metadata, the data dfs.datanode.data.dir directories must be manually removed.

Upvotes: 1

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