9.2.2. Adding a Node to a Cluster Adding a node to a cluster consists of updating the cluster configuration, propagating the updated configuration to the node to be added, and starting the cluster software on that node. To add a node to a cluster, perform the following steps: At any node in the cluster, edit the /etc/cluster/cluster.conf to add a clusternode section for the node that is to be added. For example, in Example 9.2, "Two-node Cluster Configuration" , if node-03.example.com is supposed to be added, then add a clusternode section for that node. If adding a node (or nodes) causes the cluster to transition from a two-node cluster to a cluster with three or more nodes, remove the following cman attributes from /etc/cluster/cluster.conf : cman two_node="1" expected_votes="1" Refer to Section 9.2.3, "Examples of Three-Node and Two-Node Configurations" for comparison between a three-node and a two-node configuration. Update the config_version attribute by incrementing its value (for example, changing from config_version="2" to config_version="3"> ). Save /etc/cluster/cluster.conf . (Optional) Validate the updated file against the cluster schema ( cluster.rng ) by running the ccs_config_validate command. For example: Run the cman_tool version -r command to propagate the configuration to the rest of the cluster nodes. Verify that the updated configuration file has been propagated. Propagate the updated configuration file to /etc/cluster/ in each node to be added to the cluster. For example, use the scp command to send the updated configuration file to each node to be added to the cluster. If the node count of the cluster has transitioned from two nodes to greater than two nodes, you must restart the cluster software in the existing cluster nodes as follows: At each node, stop the cluster software according to Section 9.1.2, "Stopping Cluster Software" . For example: At each node, start the cluster software according to Section 9.1.1, "Starting Cluster Software" . For example: At each node to be added to the cluster, start the cluster software according to Section 9.1.1, "Starting Cluster Software" . For example: At any node, using the clustat utility, verify that each added node is running and part of the cluster. For example: For information about using clustat , see Section 9.3, "Managing High-Availability Services" . In addition, you can use cman_tool status to verify node votes, node count, and quorum count. For example: At any node, you can use the clusvcadm utility to migrate or relocate a running service to the newly joined node. Also, you can enable any disabled services. For information about using clusvcadm , see Section 9.3, "Managing High-Availability Services" Note When you add a node to a cluster that uses UDPU transport, you must restart all nodes in the cluster for the change to take effect.

Commands:
ccs_config_validate Configuration validates
service rgmanager stop Stopping Cluster Service Manager: [ OK ] service gfs2 stop Unmounting GFS2 filesystem (/mnt/gfsA): [ OK ] Unmounting GFS2 filesystem (/mnt/gfsB): [ OK ] service clvmd stop Signaling clvmd to exit [ OK ] clvmd terminated [ OK ] service cman stop Stopping cluster: Leaving fence domain... [ OK ] Stopping gfs_controld... [ OK ] Stopping dlm_controld... [ OK ] Stopping fenced... [ OK ] Stopping cman... [ OK ] Waiting for corosync to shutdown: [ OK ] Unloading kernel modules... [ OK ] Unmounting configfs... [ OK ]
service cman start Starting cluster: Checking Network Manager... [ OK ] Global setup... [ OK ] Loading kernel modules... [ OK ] Mounting configfs... [ OK ] Starting cman... [ OK ] Waiting for quorum... [ OK ] Starting fenced... [ OK ] Starting dlm_controld... [ OK ] Starting gfs_controld... [ OK ] Unfencing self... [ OK ] Joining fence domain... [ OK ] service clvmd start Starting clvmd: [ OK ] Activating VG(s): 2 logical volume(s) in volume group "vg_example" now active [ OK ] service gfs2 start Mounting GFS2 filesystem (/mnt/gfsA): [ OK ] Mounting GFS2 filesystem (/mnt/gfsB): [ OK ] service rgmanager start Starting Cluster Service Manager: [ OK ]
service cman start Starting cluster: Checking Network Manager... [ OK ] Global setup... [ OK ] Loading kernel modules... [ OK ] Mounting configfs... [ OK ] Starting cman... [ OK ] Waiting for quorum... [ OK ] Starting fenced... [ OK ] Starting dlm_controld... [ OK ] Starting gfs_controld... [ OK ] Unfencing self... [ OK ] Joining fence domain... [ OK ] service clvmd start Starting clvmd: [ OK ] Activating VG(s): 2 logical volume(s) in volume group "vg_example" now active [ OK ] service gfs2 start Mounting GFS2 filesystem (/mnt/gfsA): [ OK ] Mounting GFS2 filesystem (/mnt/gfsB): [ OK ] service rgmanager start Starting Cluster Service Manager: [ OK ]
clustat Cluster 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
cman_tool status Version: 6.2.0 Config Version: 19 Cluster Name: mycluster Cluster Id: 3794 Cluster Member: Yes Cluster Generation: 548 Membership state: Cluster-Member Nodes: 3 Expected votes: 3 Total votes: 3 Node votes: 1 Quorum: 2 Active subsystems: 9 Flags: Ports Bound: 0 11 177 Node name: node-01.example.com Node ID: 3 Multicast addresses: 239.192.14.224 Node addresses: 10.15.90.58