Permission Denied for the user. Try checking the read and execute permission or ranger policies. ... View more

Thanks for prompt response and testing. This worked for me too previously. ... View more

@ARVINDR : Thanks for the info on that cluster creation part. Did you try to check the ACL. ... View more

@ARVINDR :   Is it happening on your production cluster or test cluster. From the error i see that there is some prob with the repo. Could you just check that.  ... View more

@ARVINDR :   seems to be acl issues :   1.pls do a directory listing from hdfs which the lock file is refering too.  2. Is that a running cluster or creating the cluster from the scratch ?      ... View more

@ARVINDR :    Do u still face issue ? Could you send the below things:   1. When u start the NN i need console logs(screen logs or ambari logs while you see the operation) 2. I need the NN logs.     ... View more

@Mondi : Yes it refers to meta data and the point in which the snapshot is done. You can revert or restore the data from the snapshot at any point in time.  https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-hdfs/HdfsSnapshots.html   ... View more

@ARVINDR    The netstat output was empty because no process is listening to your port.  The above screenshot says it's warning. Did that application started ??   Which version you are using so that we could provide you the excat documentation link.   Let me know your insight. ... View more

HDFS Snapshots are read-only point-in-time copies of the file system. Snapshots can be taken on a subtree of the file system or the entire file system. Some common use cases of snapshots are data backup, protection against user errors and disaster recovery. The implementation of HDFS Snapshots is efficient: Snapshot creation is instantaneous: the cost is O(1) excluding the inode lookup time. Additional memory is used only when modifications are made relative to a snapshot: memory usage is O(M), where M is the number of modified files/directories. Blocks in datanodes are not copied: the snapshot files record the block list and the file size. There is no data copying. Snapshots do not adversely affect regular HDFS operations: modifications are recorded in reverse chronological order so that the current data can be accessed directly. The snapshot data is computed by subtracting the modifications from the current data. ... View more