> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/pdc-10.2-data-optimizer/pdso-install-landing-page/pdso-install-in-hadoop-cluster/pdso-install-landing-page-hadoop-installation/installing-data-storage-optimizer-on-cloudera-manager-cluster-cp/refresh-hdfs-datanodes-after-adding-data-storage-optimizervolumes.md).

# Refresh HDFS Datanodes after adding Data Optimizer volumes

After you have configured HDFS data nodes to use Data Optimizer volumes, refresh or restart the data nodes so they can register the configuration change and use the volumes. The data node property that was modified is a refreshable configuration, so the data nodes can pick up new data directories without restarting, which can be disruptive.

Typically, Cloudera Manager prompts you to refresh your data nodes because Cloudera Manager detects that the configuration change is refreshable. Click the refresh icon when it appears at the top of the HDFS configuration page to refresh your data nodes. After the refresh, the data nodes can start tiering to Data Optimizer.

In some cases, such as if you created a new configuration role group, Cloudera Manager may prompt for a restart. In this case, contact the Data Optimizer implementation team and your Cluster Administrator to determine how best to proceed and resolve the required restart notifications. You still might be able to perform a refresh by executing the **Refresh Cluster** action. After the refresh, data nodes are ready to begin tiering as described in the previous paragraph.

**CAUTION:**

After HDFS has been configured to use Data Optimizer Volumes, do not stop the Volume on a node when the Datanode service is still running. Doing so can result in unpredictable behavior, including HDFS marking a volume as failed.

To verify Data Optimizer is tiering properly, see [Tiering HDFS Blocks to Data Optimizer](/pdc-10.2-data-optimizer/pdso-install-landing-page/pdso-install-in-hadoop-cluster/pdso-maintain-landing-page/troubleshoot-data-storage-optimizer-fs/tiering-hdfs-blocks-to-pdso.md).


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.pentaho.com/pdc-10.2-data-optimizer/pdso-install-landing-page/pdso-install-in-hadoop-cluster/pdso-install-landing-page-hadoop-installation/installing-data-storage-optimizer-on-cloudera-manager-cluster-cp/refresh-hdfs-datanodes-after-adding-data-storage-optimizervolumes.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.