9.4. Updating a Configuration
Updating the cluster configuration consists of editing the cluster configuration file (
/etc/cluster/cluster.conf) and propagating it to each node in the cluster. You can update the configuration using either of the following procedures:
9.4.1. Updating a Configuration Using cman_tool version -r
To update the configuration using the
cman_tool version -r command, perform the following steps:
- At any node in the cluster, edit the
/etc/cluster/cluster.conffile. - Update the
config_versionattribute by incrementing its value (for example, changing fromconfig_version="2"toconfig_version="3"). - Save
/etc/cluster/cluster.conf. - Run the
cman_tool version -rcommand to propagate the configuration to the rest of the cluster nodes. It is necessary thatriccibe running in each cluster node to be able to propagate updated cluster configuration information. - Verify that the updated
cluster.confconfiguration file has been propagated. If not, use thescpcommand to propagate it to/etc/cluster/in each cluster node. - You may skip this step (restarting cluster software) if you have made only the following configuration changes:
- Deleting a node from the cluster configuration—except where the node count changes from greater than two nodes to two nodes. For information about deleting a node from a cluster and transitioning from greater than two nodes to two nodes, see Section 9.2, “Deleting or Adding a Node”.
- Adding a node to the cluster configuration—except where the node count changes from two nodes to greater than two nodes. For information about adding a node to a cluster and transitioning from two nodes to greater than two nodes, see Section 9.2.2, “Adding a Node to a Cluster”.
- Changes to how daemons log information.
- HA service/VM maintenance (adding, editing, or deleting).
- Resource maintenance (adding, editing, or deleting).
- Failover domain maintenance (adding, editing, or deleting).
Otherwise, you must restart the cluster software as follows:- At each node, stop the cluster software according to Section 9.1.2, “Stopping Cluster Software”.
- At each node, start the cluster software according to Section 9.1.1, “Starting Cluster Software”.
Stopping and starting the cluster software ensures that any configuration changes that are checked only at startup time are included in the running configuration. - At any cluster node, run
cman_tool nodesto verify that the nodes are functioning as members in the cluster (signified as "M" in the status column, "Sts"). For example:[root@example-01 ~]#
cman_tool nodesNode Sts Inc Joined Name 1 M 548 2010-09-28 10:52:21 node-01.example.com 2 M 548 2010-09-28 10:52:21 node-02.example.com 3 M 544 2010-09-28 10:52:21 node-03.example.com - At any node, using the
clustatutility, verify that the HA services are running as expected. In addition,clustatdisplays status of the cluster nodes. For example:[root@example-01 ~]#
clustatCluster Status for mycluster @ Wed Nov 17 05:40:00 2010 Member Status: Quorate Member Name ID Status ------ ---- ---- ------ node-03.example.com 3 Online, rgmanager node-02.example.com 2 Online, rgmanager node-01.example.com 1 Online, Local, rgmanager Service Name Owner (Last) State ------- ---- ----- ------ ----- service:example_apache node-01.example.com started service:example_apache2 (none) disabled - If the cluster is running as expected, you are done updating the configuration.
