To permanently remove Cluster Nodes from the cluster, please proceed as follows:
Change the cluster configuration using dis_netconfig:
Load the existing configuration.
In the cluster settings, change the topology to match the topology with all Cluster Nodes removed.
The topology change might cut out Cluster Nodes from the cluster at the "wrong" end, you have to make sure that the hostnames and the placement within the new topology for the remaining Cluster Nodes is correct. To do this, change the hostnames of Cluster Nodes by double-clicking their icon and changing the hostname in the displayed dialog box. If the SuperSockets configuration is based on the hostnames (not on the subnet addresses), make sure that the name of the socket interface matches a modified hostname.
Save the new cluster configuration. If desired, create and save or print the cabling instructions for the reduced cluster.
If you are not running dis_netconfig or dis_mkconf on the Cluster Management Node, transfer the saved files dishosts.conf and cluster.conf to the directory /etc/dis on the Cluster Management Node.
Restart the Network Manager on the Cluster Management Node. If you run dis_admin, the removed Cluster Nodes should no longer show up. All other Cluster Nodes should continue to stay green.
Disconnect the Cluster Nodes to be removed one by one, making sure that the remaining Cluster Nodes are cabled according to the cabling instructions generated above.
On the Cluster Nodes that have been removed from the cluster, the Dolphin eXpressWare software can easily be removed using the SIA option --wipe, like:
# sh Dolphin_eXpressWare-<version>.sh --wipe
This will remove eXpressWare components, services and configuration data from the Cluster Node.
If no SIA is available, the same effect can be achieved by manually uninstalling all packages that start with Dolphin-, remove potentially remaining installation directories (like /opt/DIS), and remove the configuration directory /etc/dis.
To remove all Dolphin software from the Cluster Node, use the standard package commands to determine which packages are installed, and remove them:
# rpm -qa | grep Dol ... # rpm -e <package name> ...
Perform the cable test from within dis_admin to ensure that the cabling is correct (see Chapter 4, Initial Installation, Section 3.8.4, “PCIe connection Test”) for the remaining Cluster Nodes.
Running the cable test will stop other traffic on the interconnect for the time the test is running, which can be up to a minute. If this is not an option, please use dis_diag from the command line to verify the functionality of the interconnect (see Chapter 7, Interconnect Maintenance, Section 1.3, “Static PCIe Interconnect Test - dis_diag”).