Unable to start datanode and file permissions of datanode are changing when start-dfs.sh is started - hadoop

Question

I was facing issues in deploying local files to hdfs and found that I should have "drwx------" for datanode and namenode.
Initial permission status of datanode and namenode in hdfs.
drwx------ 3 hduser hadoop 4096 Mar 2 16:45 datanode
drwxr-xr-x 3 hduser hadoop 4096 Mar 2 17:30 namenode
Permission of datanode is changed to 755
hduser#pradeep:~$ chmod -R 755 /usr/local/hadoop_store/hdfs/
hduser#pradeep:~$ ls -l /usr/local/hadoop_store/hdfs/
total 8
drwxr-xr-x 3 hduser hadoop 4096 Mar 2 16:45 datanode
drwxr-xr-x 3 hduser hadoop 4096 Mar 2 17:30 namenode
After initiating start-dfs.sh, datanode didn't start and permissions to datanode were restored to original state.
hduser#pradeep:~$ $HADOOP_HOME/sbin/start-dfs.sh
Starting namenodes on [localhost]
localhost: starting namenode, logging to /usr/local/hadoop/logs/hadoop- hduser-namenode-pradeep.out
localhost: starting datanode, logging to /usr/local/hadoop/logs/hadoop-hduser-datanode-pradeep.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: starting secondarynamenode, logging to /usr/local/hadoop/logs/hadoop-hduser-secondarynamenode-pradeep.out
hduser#pradeep:~$ jps
4385 Jps
3903 NameNode
4255 SecondaryNameNode
hduser#pradeep:~$ ls -l /usr/local/hadoop_store/hdfs/
total 8
drwx------ 3 hduser hadoop 4096 Mar 2 22:34 datanode
drwxr-xr-x 3 hduser hadoop 4096 Mar 2 22:34 namenode
As datanode is not running i am not able to deploy data to hdfs from local file system. I couldn't understand or find any reason why the file permissions are restored to previous state only for datanode folder.

Answer 1

it appears the name space id generated by the NameNode is different from your DataNode.
Solution:
if you goto the path where your hadoop files are stored on the local file system.
forexample /usr/local/hadoop. go down the path to /usr/local/hadoop/tmp/dfs/name/version. copy the namespaceid and take it to the path /usr/local/hadoop/tmp/dfs/data/version , replace the namespaceid.
i hope this helps.