8.4.5. Configuration Overview: KVM Guest Node This section provides a high-level summary overview of the steps to perform to have Pacemaker launch a virtual machine and to integrate that machine as a guest node, using libvirt and KVM virtual guests. After installing the virtualization software and enabling the libvirtd service on the cluster nodes, put the same encryption key with the path /etc/pacemaker/authkey on every cluster node and virtual machine. This secures remote communication and authentication. Run the following set of commands on every node to create the authkey directory with secure permissions. The following command shows one method to create an encryption key. You should create the key only once and then copy it to all of the nodes. On every virtual machine, install pacemaker_remote packages, start the pacemaker_remote service and enable it to run on startup, and allow TCP port 3121 through the firewall. Give each virtual machine a static network address and unique host name, which should be known to all nodes. For information on setting a static IP address for the guest virtual machine, see the Virtualization Deployment and Administration Guide . To create the VirtualDomain resource agent for the management of the virtual machine, Pacemaker requires the virtual machine's xml config file to be dumped to a file on disk. For example, if you created a virtual machine named guest1 , dump the xml to a file somewhere on the host. You can use a file name of your choosing; this example uses /etc/pacemaker/guest1.xml . If it is running, shut down the guest node. Pacemaker will start the node when it is configured in the cluster. Create the VirtualDomain resource, configuring the remote-note resource meta option to indicate that the virtual machine is a guest node capable of running resources. In the example below, the meta-attribute remote-node=guest1 tells pacemaker that this resource is a guest node with the host name guest1 that is capable of being integrated into the cluster. The cluster will attempt to contact the virtual machine's pacemaker_remote service at the host name guest1 after it launches. From a cluster node, enter the following command. 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. As of Red Hat Enterprise Linux 6.8, you can include guest nodes in groups, which allows you to group a storage device, file system, and VM.

Commands:
mkdir -p --mode=0750 /etc/pacemaker chgrp haclient /etc/pacemaker
dd if=/dev/urandom of=/etc/pacemaker/authkey bs=4096 count=1
yum install pacemaker-remote resource-agents systemctl start pacemaker_remote.service systemctl enable pacemaker_remote.service firewall-cmd --add-port 3121/tcp --permanent firewall-cmd --reload
virsh dumpxml guest1 > /etc/pacemaker/guest1.xml
pcs resource create vm-guest1 VirtualDomain hypervisor="qemu:///system" config="/virtual_machines/vm-guest1.xml" meta remote-node=guest1
pcs resource create webserver apache configfile=/etc/httpd/conf/httpd.conf op monitor interval=30s pcs constraint location webserver prefers guest1