Transparent Upgrade

A Transparent Upgrade is one in which services run without interruption throughout the cluster, during the upgrade. In a Transparent Upgrade, service software remains running without the benefit of oversight by the ClusterResourceManager or LocalResourceManager.

Nodes in the cluster are upgraded, either one at a time or all at once, and then control of the services is returned to the ClusterResourceManager either at the end or incrementally at the end of each node upgrade.

This is distinct from a RollingUpgrade in which case all services remain at all times under the supervision of the ClusterResourceManager and LocalResourceManager.

CRM transparent upgrade quick howto

The CRM clusters are very easy to upgrade transparently. A quick howto follows, but first a word of

WARNING: Always first test the new release with the existing configuration on a test cluster.

Now that you read and understood properly the previous note, here are the steps for a transparent upgrade:

1. Set all resources to the unmanaged mode:

    # crm_attribute -t crm_config -n is-managed-default -v false 

   Note that after the release 2.0.8 the attribute name changed from is_managed_default.

2. Check that all resources are unmanaged:

    # crm_mon -1

   If some are not, then remove the attribute from those resources:

    # crm_resource -r <rsc> --meta -d is_managed

3. Now you can stop heartbeat, upgrade, start.

   NB: In case the heartbeat does not want to stop, just kill all the processes.

4. Put resources back into the managed mode:

    # crm_attribute -t crm_config -n is-managed-default -v true

See Also

RollingUpgrade

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