Chapter 7. Testing the NFS Cluster Service

After you have configured the NFS service, you can check to be sure that the NFS service is working and that it will continue to work as expected if one of the nodes goes down. The following procedure tests an NFS mount on a client, fences the node on which the NFS service is running, and then checks to be sure that the NFS client can still access the file system.
  1. If the GFS file system in the nfsclust cluster is currently empty, populate the file system with test data.
  2. Log in to one of the client systems you defined as a target.
  3. Mount the NFS file system on the client system, and check to see if the data on that file system as available.
  4. On the Luci server, select Nodes from the menu for nfsclust. This displays the nodes in nfsclust and indicates which node is running the nfssvc service.
  5. The drop-down box for each node displays Choose a task. For the node on which the nfssvc service is running, select Fence this node.
  6. Refresh the screen. The nfssvc service should now be running in a different node.
  7. On the client system, check whether the file system you mounted is still available. Even though the NFS service is now running on a different node in the cluster, the client system should detect no difference.
  8. Restore the system to its previous state:
    • Unmount the file system from the client system.
    • Delete any test data you created in the GFS file system.
    • Click on Choose a task in the drop-down box for the node which you fenced and select Reboot this node.

Note

For advanced troubleshooting once a system has gone into production, it is sometimes necessary to set up the netconsole and kdump services on a system. You may find it useful to implement and test these tools before a system goes into production, to help in troubleshooting down the line.