Support Questions
Find answers, ask questions, and share your expertise
Alert: Welcome to the Unified Cloudera Community. Former HCC members be sure to read and learn how to activate your account here.

Who agreed with this solution

Re: New Disk in Data Node

Community Manager

The HDFS Balancer only balances blocks between DataNodes.   It does not to any balancing on individual DataNodes between drives.


You can set the DataNode Volume Choosing Policy (dfs.datanode.fsdataset.volume.choosing.policy) to Available Space (org.apache.hadoop.hdfs.server.datanode.fsdataset.AvailableSpaceVolumeChoosingPolicy).  This will cause the DataNodes to write new blocks to the drive with the most space available.   It does not affect blocks that have already been written.


For your question about wiping one datanode at a time, it would be better to decommission and then recommission a node.  With a replication factor of 3 you may perform this action on 2 nodes at a time.



David Wilder, Community Manager

Was your question answered? Make sure to mark the answer as the accepted solution.
If you find a reply useful, say thanks by clicking on the thumbs up button.

Learn more about the Cloudera Community:

Terms of Service

Community Guidelines

How to use the forum

View solution in original post

Who agreed with this solution