If you move a node physically without changing the cabling, it is obvious that no configuration change are necessary.
If however you have to exchange two nodes, or for other reasons place a node which has been part of the cluster at another position within the interconnect that requires the node to be connected to other nodes than before, then this change has to reflect in the cluster configuration as well. This can easily be done using either dishostseditor or a plain text editor.
Please proceed as follows:
Power down all nodes that are to be moved. The network manager will automatically reroute the interconnect traffic. When you run sciadmin on the frontend, you will see the icon of the node turn red within the GUI representation of the cluster nodes.
Powering down more than one node will make other nodes not accessible via SCI if the powered-down nodes are not located within one ringlet.
Move the nodes to the new location and connect the cables to the adapters. Do not yet power them up!
Update the cluster configuration file /etc/dis/dishosts.conf on the frontend by either using dishostseditor or a plain text editor:
If using dishostseditor, load the original configuration (by running dishostseditor on the frontend, it will be loaded automatically) and change the positions of the nodes within the torus. Save the new configuration.
When using a plain text editor, exchange the hostnames of the nodes in this file. You can also change the adapter and socket names accordingly (which typically contain the hostnames), but this will not affect functionality.
Restart the network manager on the frontend to make the changed configuration effective.
Power up the nodes. Once they come up, their configuration will be change by the network manager to reflect their new position within the interconnect.