3.2.2. Adding Cluster Nodes
Note
It is highly recommended that you add nodes to existing clusters only during a production maintenance window. This allows you to perform appropriate resource and deployment testing for the new node and its fencing configuration.
Use the following procedure to add a new node to an existing cluster. In this example, the existing cluster nodes are
clusternode-01.example.com, clusternode-02.example.com, and clusternode-03.example.com. The new node is newnode.example.com.
On the new node to add to the cluster, perform the following tasks.
- Install the cluster packages. If the cluster uses SBD, you must manually install the
sbdpackage on the new node as well.[root@newnode ~]#
yum install -y pacemaker cman pcs - To prevent
corosyncfrom starting withoutcman, execute the following command:[root@newnode ~]#
chkconfig corosync off - Set a password for the user ID
hacluster. It is recommended that you use the same password for each node in the cluster.[root@newnode ~]#
passwd haclusterChanging password for user hacluster. New password: Retype new password: passwd: all authentication tokens updated successfully. - Start and enable
pcsdon the new node:[root@newnode ~]#
service pcsd start[root@newnode ~]#chkconfig pcsd on
On a node in the existing cluster, perform the following tasks.
- Authenticate user
haclusteron the new cluster node.[root@clusternode-01 ~]#
pcs cluster auth newnode.example.comUsername: hacluster Password: newnode.example.com: Authorized - Add the new node to the existing cluster. This command also syncs the cluster configuration file
cluster.confto all nodes in the cluster, including the new node you are adding.[root@clusternode-01 ~]#
pcs cluster node add newnode.example.comclusternode-01.example.com: Corosync updated clusternode-02.example.com: Corosync updated clusternode-03.example.com: Corosync updated newnode.example.com: Updated cluster.conf... newnode.example.com: Starting Cluster...
On the new node to add to the cluster, perform the following tasks.
- Enable cluster services on the new node. In Red Hat Enterprise Linux 6, the new node is started automatically by PCS.
[root@newnode ~]#
pcs cluster enable - Ensure that you configure and test a fencing device for the new cluster node. For information on configuring fencing devices, see Chapter 4, Fencing: Configuring STONITH.
