question Re: Decommissioned datanode/regionserver: is it safe to remove /dfs directory to free disk-space in Archives of Support Questions (Read Only)

Decommissioned datanode/regionserver: is it safe to remove /dfs directory to free disk-space

akshay008 — Fri, 16 Sep 2022 09:47:54 GMT

Hi List,

I have disk space limitation on couple of my datanodes (also have regionserver and nodemanager roles on them). It is on a public cloud, I already have the largest disk and they would not give me more disk.
These machines are also running other high-priority processes (other than CDH processes), which needs disk space. So I want to free up space by taking hbase/hdfs off it and distribute the data to other nodes in the cluster.

I have decommissioned the nodes and deleted the roles from the hosts but that does not free up /dfs directory on the hosts (still taking most of my disk space).
Is it OK to directly delete the /dfs directory from the nodes, or make it empty? I want the flexibility of adding them back to the cluster at some point of time (may be once I have more disk), if I need to. I am hoping I am not the first one in this situation, any suggestions/work-arounds would be appreciated.

Thanks,

Akshay

Re: Decommissioned datanode/regionserver: is it safe to remove /dfs directory to free disk-space

akshay008 — Mon, 09 Nov 2015 15:28:16 GMT

Bump up.

Sorry still confused about it.

Re: Decommissioned datanode/regionserver: is it safe to remove /dfs directory to free disk-space

michalis — Mon, 09 Nov 2015 22:27:51 GMT

Happy to say that our in documentation we have noted that when a DataNode is decommissioned, the data blocks are not removed from the storage directories. You must delete the data manually.

Re: Decommissioned datanode/regionserver: is it safe to remove /dfs directory to free disk-space

akshay008 — Tue, 10 Nov 2015 13:27:20 GMT

Thanks Michalis.

I believe if I have to add this back to the cluster, those directories (of course based on configurations) would be created again.

Re: Decommissioned datanode/regionserver: is it safe to remove /dfs directory to free disk-space

quangbilly79 — Wed, 24 Sep 2025 02:10:59 GMT

Hi, I'm in the same situation. Are there any problems when you add the DataNode back after decomissioning and delete data folder?