Troubleshooting the MapR Data Fabric for Kubernetes

This section describes how to resolve common problems you might encounter when using the MapR Data Fabric for Kubernetes.

Shared Memory Lock Causes POSIX Failure

Problem

After upgrading the MapR Data Fabric for Kubernetes and exercising the volume plug-in, POSIX fails with the following error: Create/Attach to stats shared memory failed.

Possible Cause

A shared-memory segment lock can prevent the mount from becoming available to the requested pod.

Resolution

Follow the steps in Troubleshooting MapR POSIX Client Upgrades to remove the lock. Then retry the operation.

Unable to Access MapR-FS

Problem

Storage is not mounted and no errors are generated in the plugin or provisioner logs.

Possible Cause

The fusermount symlink might be broken.

Resolution
If the symlink points to a location other than /opt/mapr/k8s/bin/fusermount, unlink it using the following command from the command line on the host:
unlink /bin/fusermount
Then re-create the Kubernetes Pod.

Pod Container Stuck in Container Creation State During Installation

Problem
During installation, the Pod container can become stuck in the container creation state on a node, and the/opt/mapr/k8s directory is not created. As a result, the plug-in does not get copied to the node.
Possible Cause
Unknown.
Resolution
Check the installation logs for an indication that the installation is not completed or the /opt/mapr/k8s directory is not created. Restart the kubelet service in the node:
systemctl restart kubelet