5.5.2. Adding a Member to a Running DLM Cluster

The procedure for adding a member to a running DLM cluster depends on whether the cluster contains only two nodes or more than two nodes. To add a member to a running DLM cluster, follow the steps in one of the following sections according to the number of nodes in the cluster:

5.5.2.1. Adding a Member to a Running DLM Cluster That Contains Only Two Nodes

To add a member to an existing DLM cluster that is currently in operation, and contains only two nodes, follow these steps:
  1. Add the node and configure fencing for it as in Section 5.5.1, “Adding a Member to a New Cluster”.
  2. Click Send to Cluster to propagate the updated configuration to other running nodes in the cluster.
  3. Use the scp command to send the updated /etc/cluster/cluster.conf file from one of the existing cluster nodes to the new node.
  4. At system-config-cluster, in the Cluster Status Tool tab, disable each service listed under Services.
  5. Stop the cluster software on the two running nodes by running the following commands at each node in this order:
    1. service rgmanager stop, if the cluster is running high-availability services (rgmanager)
    2. service gfs stop, if you are using Red Hat GFS
    3. service clvmd stop, if CLVM has been used to create clustered volumes
    4. service fenced stop
    5. service cman stop
    6. service ccsd stop
  6. Start cluster software on all cluster nodes (including the added one) by running the following commands in this order:
    1. service ccsd start
    2. service cman start
    3. service fenced start
    4. service clvmd start, if CLVM has been used to create clustered volumes
    5. service gfs start, if you are using Red Hat GFS
    6. service rgmanager start, if the cluster is running high-availability services (rgmanager)
  7. Start system-config-cluster (refer to Section 5.2, “Starting the Cluster Configuration Tool). At the Cluster Configuration Tool tab, verify that the configuration is correct. At the Cluster Status Tool tab verify that the nodes and services are running as expected.

Note

Make sure to configure other parameters that may be affected by changes in this section. Refer to Section 5.1, “Configuration Tasks”.