Unable to mount CephFS using Alluxio 2.9.4 in Kubernetes 1.28 (via Helm chart)

[sky-tower]

Description:

I'm facing an issue when trying to mount CephFS using Alluxio version 2.9.4 deployed on Kubernetes 1.28. The installation was done via the Alluxio Helm chart (integration/kubernetes/helm-chart/alluxio). When attempting to mount CephFS from the alluxio-master container using the following command, I receive the error "Unable to create an UnderFileSystem instance for path."

Steps to Reproduce:

1. Deployed Alluxio on Kubernetes using the Helm chart.
2. Using Alluxio version 2.9.4.
3. Executed the following mount command inside the alluxio-master container:

   ./alluxio fs mount \
   --option name="***" \
   --option secret="***" \
   /mnt/cephfs/ cephfs://10.9.0.6:6789,10.9.0.7:6789,10.9.0.5:6789/

4. The command returns the following error:

   mount command: alluxio fs mount /mnt/cephfs cephfs://10.9.0.6:6789,10.9.0.7:6789,10.9.0.5:6789/ option MountContext{ProtoOptions=readOnly: false
   properties {
     key: "name"
     value: "***"
   }
   properties {
     key: "secret"
     value: "***"
   }
   shared: false
   commonOptions {
     ttl: -1
     ttlAction: FREE
   }
   }
   Acquired mount ID for the new mount point: 470124985186816983
   Unable to create an UnderFileSystem instance for path: cephfs://10.9.0.6:6789,10.9.0.7:6789,10.9.0.5:6789/
   

Expected Behavior:

I expected the CephFS to be successfully mounted on Alluxio without any errors, allowing me to access it as a mounted file system within the Alluxio environment.

Actual Behavior:

The mount command fails with the message: "Unable to create an UnderFileSystem instance for path: cephfs://10.9.0.6:6789,10.9.0.7:6789,10.9.0.5:6789/"

Environment:

• Alluxio version: 2.9.4
• Kubernetes version: 1.28
• Installation method: Deployed via Helm chart (integration/kubernetes/helm-chart/alluxio)
• Running in Alluxio master container

Additional Information:

• I have confirmed that the CephFS cluster is reachable and that the CephFS credentials are correct.

Potential Fix:

Could you please investigate why the CephFS mount fails, and provide any guidance on configuration or possible fixes? Thank you!

[YichuanSun]

Please check whether ceph-related *.jar exists in ALLUXIO_WORK_DIRECTORY/lib/. By the way, it'd be better if any client side log is provided.