hadoop - Name node is in safe mode. Not able to leave

Question

root# bin/hadoop fs -mkdir t
mkdir: org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory /user/root/t. Name node is in safe mode.

not able to create anything in hdfs

I did

root# bin/hadoop fs -safemode leave

But showing

safemode: Unknown command

what is the problem?

Solution: http://unmeshasreeveni.blogspot.com/2014/04/name-node-is-in-safe-mode-how-to-leave.html?m=1

Answer 1

In order to forcefully let the namenode leave safemode, following command should be executed:

 bin/hadoop dfsadmin -safemode leave

You are getting Unknown command error for your command as -safemode isn't a sub-command for hadoop fs, but it is of hadoop dfsadmin.

Also after the above command, I would suggest you to once run hadoop fsck so that any inconsistencies crept in the hdfs might be sorted out.

Update:

Use hdfs command instead of hadoop command for newer distributions. The hadoop command is being deprecated:

hdfs dfsadmin -safemode leave

hadoop dfsadmin has been deprecated and so is hadoop fs command, all hdfs related tasks are being moved to a separate command hdfs.