Rook (Ceph Operator) MGR_MODULE_NOT_FOUND error encountered during Ceph cluster operations.

What is Rook (Ceph Operator) MGR_MODULE_NOT_FOUND error encountered during Ceph cluster operations.

Understanding Rook (Ceph Operator)

Rook is an open-source cloud-native storage orchestrator for Kubernetes, which leverages the Ceph storage system to provide reliable and scalable storage solutions. The Rook (Ceph Operator) automates the deployment, configuration, and management of Ceph clusters within Kubernetes environments. It simplifies the complex task of managing storage by providing a seamless integration with Kubernetes, making it easier for developers to manage storage resources.

Identifying the Symptom

When working with Rook (Ceph Operator), you might encounter the MGR_MODULE_NOT_FOUND error. This error typically appears in the logs or status outputs when a specified manager module cannot be found. This can disrupt the normal operation of the Ceph cluster, leading to potential issues with storage management and monitoring.

Explaining the MGR_MODULE_NOT_FOUND Issue

The MGR_MODULE_NOT_FOUND error indicates that a particular manager module, which is expected to be present and active, is missing. Ceph manager modules are essential for providing additional functionalities such as monitoring, dashboards, and other management features. If a module is not found, it could be due to an incorrect configuration or the module not being installed or enabled in the cluster.

Common Causes

Incorrect module name specified in the configuration. The module is not installed or enabled in the Ceph cluster. Configuration files are not properly updated or synced.

Steps to Fix the MGR_MODULE_NOT_FOUND Issue

To resolve the MGR_MODULE_NOT_FOUND error, follow these detailed steps:

Step 1: Verify the Module Name

Ensure that the module name specified in your configuration is correct. You can list all available modules using the following command:

ceph mgr module ls

This command will display all the modules that are available and enabled in your Ceph cluster. Verify that the module you are trying to use is listed.

Step 2: Enable the Missing Module

If the module is not enabled, you can enable it using the following command:

ceph mgr module enable <module_name>

Replace <module_name> with the actual name of the module you wish to enable. This should resolve the issue if the module was simply not enabled.

Step 3: Update Configuration Files

Ensure that your configuration files are up-to-date and correctly specify the modules you intend to use. Check the ceph.conf file and any other relevant configuration files for accuracy.

Step 4: Restart the Ceph Manager

After making changes, restart the Ceph manager to apply the new configuration:

ceph mgr restart

This will reload the manager with the updated settings and should resolve any lingering issues related to the module not being found.

Additional Resources

For further information, you can refer to the official Rook Ceph Quickstart Guide and the Ceph Manager Modules Documentation. These resources provide comprehensive guidance on managing and troubleshooting Ceph clusters with Rook.