30.2. Configuring KVM guest nodes

Procedure

1. Configure the VirtualDomain resources.

2. Enter the following commands on every virtual machine to install pacemaker_remote packages, start the pcsd service and enable it to run on startup, and allow TCP port 3121 through the firewall.

   # dnf install pacemaker-remote resource-agents pcs
   # systemctl start pcsd.service
   # systemctl enable pcsd.service
   # firewall-cmd --add-port 3121/tcp --permanent
   # firewall-cmd --add-port 2224/tcp --permanent
   # firewall-cmd --reload

3. Give each virtual machine a static network address and unique host name, which should be known to all nodes.

4. If you have not already done so, authenticate pcs to the node you will be integrating as a quest node.

   # pcs host auth nodename

5. Use the following command to convert an existing VirtualDomain resource into a guest node. This command must be run on a cluster node and not on the guest node which is being added. In addition to converting the resource, this command copies the /etc/pacemaker/authkey to the guest node and starts and enables the pacemaker_remote daemon on the guest node. The node name for the guest node, which you can define arbitrarily, can differ from the host name for the node.

   # pcs cluster node add-guest nodename resource_id [options]

6. After creating the VirtualDomain resource, you can treat the guest node just as you would treat any other node in the cluster. For example, you can create a resource and place a resource constraint on the resource to run on the guest node as in the following commands, which are run from a cluster node. You can include guest nodes in groups, which allows you to group a storage device, file system, and VM.

   # pcs resource create webserver apache configfile=/etc/httpd/conf/httpd.conf op monitor interval=30s
   # pcs constraint location webserver prefers nodename