Hadoop temp direcotry issue - namenode disappear while restarting.

Hadoop temp direcotry issue 

While running hadoop in psudo-distributed mode  you may see the error

'directory /tmp/hadoop-{user}/dfs/name is inconsistent state'.

This happens because each system shutdown cleans up unwanted temp folders and files from /tmp folder.So pointing your hadoop dfs location other than default /tmp folder will solve this issue.

You can edit onf/hdfs-site.xml and set dfs location specific to your box

<property>
  <name>dfs.name.dir</name>
  <value>/hadoopstorage/name/</value>
</property>

<property>
  <name>dfs.data.dir</name>
  <value>/hadoopstorage/data/</value>
</property>

This will remove namenode, datanode errors. But you may get errors related jobtracker and other process still the most other files pointing to the default /tmp directory.

The default value for all of the hadoop related directories will be like below.

• dfs.name.dir -> ${hadoop.tmp.dir}/dfs/name.
• dfs.data.dir -> ${hadoop.tmp.dir}/dfs/data.
• fs.checkpoint.dir:-> ${hadoop.tmp.dir}/dfs/namesecondary.

One quick solution is to change hadoop tmp directory to point folder of your interest.

Edit hdfs-site.xml as below

<configuration>
     <property>
         <name>dfs.replication</name>
         <value>1</value>
     </property>
     <property>
          <name>hadoop.tmp.dir</name>
          <value>/hadoopstorage/hadoop-${user.name}</value>
     </property>
</configuration>