5.5.3. Deleting a Member from a DLM Cluster

To delete a member from an existing DLM cluster that is currently in operation, follow these steps:
  1. At one of the running nodes (not at a node to be deleted), start system-config-cluster (refer to Section 5.2, “Starting the Cluster Configuration Tool). At the Cluster Status Tool tab, under Services, disable or relocate each service that is running on the node to be deleted.
  2. Stop the cluster software on the node to be deleted by running the following commands at that 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
  3. At system-config-cluster (running on a node that is not to be deleted), in the Cluster Configuration Tool tab, delete the member as follows:
    1. If necessary, click the triangle icon to expand the Cluster Nodes property.
    2. Select the cluster node to be deleted. At the bottom of the right frame (labeled Properties), click the Delete Node button.
    3. Clicking the Delete Node button causes a warning dialog box to be displayed requesting confirmation of the deletion (Figure 5.7, “Confirm Deleting a Member”).
      Confirm Deleting a Member

      Figure 5.7. Confirm Deleting a Member

    4. At that dialog box, click Yes to confirm deletion.
    5. Propagate the updated configuration by clicking the Send to Cluster button. (Propagating the updated configuration automatically saves the configuration.)
  4. Stop the cluster software on the remaining 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
  5. Start cluster software on all remaining cluster nodes 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)
  6. At system-config-cluster (running on a node that was not deleted), in 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”.