Once your Pacemaker cluster is set up, it is recommended to set a few basic cluster properties. To do so, start the crm shell and change into the configuration menu by entering configure. Alternatively. you may jump straight into the Pacemaker configuration menu by typing crm configure directly from a shell prompt. Then, set the following properties: property no-quorum-policy="ignore" \ # pe-warn-series-max="1000" \ # pe-input-series-max="1000" \ pe-error-series-max="1000" \ cluster-recheck-interval="5min" # Setting no-quorum-policy="ignore" is required in 2-node Pacemaker clusters for the following reason: if quorum enforcement is enabled, and one of the two nodes fails, then the remaining node can not establish a majority of quorum votes necessary to run services, and thus it is unable to take over any resources. In this case, the appropriate workaround is to ignore loss of quorum in the cluster. This should only only be done in 2-node clusters: do not set this property in Pacemaker clusters with more than two nodes. Note that a two-node cluster with this setting exposes a risk of split-brain because either half of the cluster, or both, are able to become active in the event that both nodes remain online but lose communication with one another. The preferred configuration is 3 or more nodes per cluster. Setting pe-warn-series-max, pe-input-series-max and pe-error-series-max to 1000 instructs Pacemaker to keep a longer history of the inputs processed, and errors and warnings generated, by its Policy Engine. This history is typically useful in case cluster troubleshooting becomes necessary. Pacemaker uses an event-driven approach to cluster state processing. However, certain Pacemaker actions occur at a configurable interval, cluster-recheck-interval, which defaults to 15 minutes. It is usually prudent to reduce this to a shorter interval, such as 5 or 3 minutes. Once you have made these changes, you may commit the updated configuration.