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SUSE Linux Enterprise High Availability 16.0

Performing Maintenance Tasks on Cluster Resources

Publication Date: 17 Jul 2026

High Availability clusters require extra preparation steps before you can perform maintenance tasks, or you risk side effects such as resource failure, unsynchronized CIBs, or data loss. Use this workflow when you need to manually manage applications or services without interference from the cluster. This involves putting one or more resources into maintenance mode so you can temporarily manage them manually.

Tip

If this isn't the workflow you need, see Section 5, “Other maintenance workflows” to choose the right one.

Important
Important: Maintenance window

Preparing resources for maintenance only takes a moment, but the length of the maintenance window depends on the tasks you need to perform. The resources that are in maintenance mode won't be highly available during the maintenance window.

1 What are HA administrative modes?

 

While under High Availability cluster management, resources must not be started or stopped from outside the cluster (for example, with systemctl). This means that if you need to manually touch a resource, you must release it from cluster management first. Resources are also vulnerable if something goes wrong when you make changes to the cluster nodes or infrastructure. You must protect the cluster and its resources before performing maintenance tasks or you risk unwanted side effects such as resource failure, unsynchronized CIBs, or even data loss.

1.1 Basic steps

 

These are the basic steps for performing any maintenance tasks in a High Availability cluster:

  1. Determine the workflow you need, depending on your maintenance tasks.

  2. Apply one or more administrative modes, depending on the workflow.

  3. Perform your maintenance tasks on the cluster, node or individual resource.

  4. Put the cluster, node or resource back into “normal” operation.

1.2 Administrative modes

 

SUSE Linux Enterprise High Availability has the following modes for protecting the cluster during maintenance tasks. Depending on your task, you might need to use one of these modes or a combination of multiple modes.

Stopping the cluster services

Stopping the cluster services means stopping Pacemaker and Corosync. In this mode, the cluster is no longer running, either entirely or just on one node. Use this mode when you need to manage infrastructure, such as storage or networking, or when you need to change the configuration of the cluster services.

  • For the whole cluster: Stopping the cluster services on all nodes at once allows you to shut down a cluster while avoiding the mass migration of resources that would happen if you shut down each node one by one. When this mode is used on its own, all the resources stop. However, this doesn't guarantee a graceful shutdown. If stopping a resource fails or times out, the resource's node is fenced. Alternatively, you can avoid resource downtime by using this mode in combination with maintenance mode.

  • For one node: Stopping the cluster services on just one node allows the rest of the cluster to continue running while you perform maintenance tasks on the offline node. The node's resources either move to another node, or stop if constraints prevent them from moving. However, if stopping a resource fails or times out, the node is fenced. To avoid attempting to stop resources and the cluster services at the same time, we recommend using this mode in combination with standby mode.

Maintenance mode

In maintenance mode, the cluster stops managing the resources and won't start, stop or monitor them. This allows you to manually manage applications or services without interference from the cluster. However, resources aren't highly available while in this mode, so they won't fail over to another node if the current node shuts down or reboots.

  • For the whole cluster: Cluster maintenance mode puts all the resources into maintenance mode at once. If you stop or restart the cluster services while in this mode, most resources can continue to run even while the cluster is offline. This allows you to make cluster configuration changes with minimal resource downtime. However, any resources that depend on Corosync, such as DLM, must be stopped.

  • For one node: Node maintenance mode puts all the resources that are running on a specific node into maintenance mode at once. Don't stop or restart the cluster services while in this mode. Without proper caution, this can lead to undesirable effects, such as concurrency violations, where resources mistakenly run on multiple nodes instead of only one node.

  • For one resource: Resource maintenance mode puts a single resource into maintenance mode. You can also put groups and clones into resource maintenance mode.

Standby mode

When a node is in standby mode, it can't run resources. Any resources that were running on it either move to another node, or stop if constraints prevent them from moving. Standby mode gives the resources more time to move or stop successfully because they aren't limited by the shutdown timeout of the cluster services. Therefore, this mode is useful for gracefully evacuating a node before stopping the cluster services or rebooting the node.

Unmanaged mode

When a resource is in unmanaged mode, the cluster won't start or stop it. However, unlike maintenance mode, the cluster still monitors the resource and reports any failures. This can be useful for troubleshooting. In most other cases, maintenance mode is more appropriate.

1.3 For more information

 

For more information, see https://clusterlabs.org/projects/pacemaker/doc/3.0/Pacemaker_Administration/html/administrative.html.

2 Enabling maintenance mode

 

Maintenance mode allows you to manually manage applications or services without interference from the cluster. You can put a resource, a node, or even the whole cluster into maintenance mode, depending on the scope of your planned changes.

When choosing the type of maintenance mode to use, keep in mind that your changes must be invisible to the cluster until you disable maintenance mode. Therefore, you must carefully evaluate any dependencies between the resources. For example, a resource could be in an ordering or colocation constraint with other resources, either on the same node or on different nodes.

2.1 Putting the cluster into maintenance mode

 

Cluster maintenance mode puts all the resources into maintenance mode at once. The cluster stops managing the resources and won't start, stop or monitor them.

Warning
Warning: No cluster protection while in maintenance mode

Resources aren't highly available while in maintenance mode, so they won't fail over to another node if the current node shuts down or reboots.

  • CRM Shell
  • Hawk

You can perform this procedure on any node in the cluster.

  1. Log in either as the root user or as a user with sudo privileges.

  2. Put the cluster into maintenance mode: 

    > sudo crm maintenance on

  3. Check the status of the cluster: 

    > sudo crm status

    The resources should all show the status maintenance.

2.2 Putting a node into maintenance mode

 

Node maintenance mode puts all the resources that are running on a specific node into maintenance mode at once. The cluster stops managing the resources and won't start, stop or monitor them.

Warning
Warning: No cluster protection while in maintenance mode

Resources aren't highly available while in maintenance mode, so they won't fail over to another node if the current node shuts down or reboots.

  • CRM Shell
  • Hawk

Perform this procedure on the node you want to put into maintenance mode.

  1. Log in to the node either as the root user or as a user with sudo privileges.

  2. Put the node into maintenance mode: 

    > sudo crm node maintenance

  3. Check the status of the cluster: 

    > sudo crm status

    The node and its resources should show the status maintenance.

2.3 Putting a resource into maintenance mode

 

Resource maintenance mode puts a single resource into maintenance mode. The cluster stops managing the resource and won't start, stop or monitor it. You can also put groups and clones into resource maintenance mode.

Warning
Warning: No cluster protection while in maintenance mode

Resources aren't highly available while in maintenance mode, so they won't fail over to another node if the current node shuts down or reboots.

  • CRM Shell
  • Hawk

You can perform this procedure on any node in the cluster.

  1. Log in either as the root user or as a user with sudo privileges.

  2. Put the resource into maintenance mode: 

    > sudo crm resource maintenance RESOURCE on

  3. Check the status of the cluster: 

    > sudo crm status

    The resource should show the status maintenance.

3 Performing the maintenance tasks

 

Perform your maintenance tasks on the application or service that the resource represents. This could be updating a virtual machine, reconfiguring a file system, or manually restarting an application, for example.

Warning
Warning: Don't shut down or reboot cluster nodes

In this workflow, don't shut down or reboot any cluster nodes. The resources aren't highly available while in maintenance mode, so they won't fail over to another node.

4 Disabling maintenance mode

 

Disable maintenance mode to put the resources back into normal operation and make them highly available again. Make sure you choose the correct procedure to disable the same type of maintenance mode you enabled earlier:

4.1 Taking the cluster out of maintenance mode

 

Taking the cluster out of maintenance mode puts the resources back under cluster management and protection.

  • CRM Shell
  • Hawk

You can perform this procedure on any node in the cluster.

  1. Log in either as the root user or as a user with sudo privileges.

  2. Check the status of the cluster: 

    > sudo crm status

    If the nodes have the status UNCLEAN (Offline), wait until they change to Online.

  3. If the nodes are Online, put the cluster back into normal operation: 

    > sudo crm maintenance off

  4. Check the status of the cluster again. The resources should no longer show the status maintenance.

4.2 Taking a node out of maintenance mode

 

Taking a node out of maintenance mode puts the resources back under cluster management and protection.

  • CRM Shell
  • Hawk

Perform this procedure on the node you want to take out of maintenance mode.

  1. Log in to the node either as the root user or as a user with sudo privileges.

  2. Put the node back into normal operation: 

    > sudo crm node ready

  3. Check the status of the cluster: 

    > sudo crm status

    The node and its resources should no longer show the status maintenance.

4.3 Taking a resource out of maintenance mode

 

Taking a resource out of maintenance mode puts it back under cluster management and protection.

  • CRM Shell
  • Hawk

You can perform this procedure on any node in the cluster.

  1. Log in either as the root user or as a user with sudo privileges.

  2. Put the resource back into normal operation: 

    > sudo crm resource maintenance RESOURCE off

  3. Check the status of the cluster: 

    > sudo crm status

    The resource should no longer show the status maintenance.

5 Other maintenance workflows

 

If you need a different workflow, or to perform a specific task, check this list of other articles:

General workflows

These articles describe general workflows for different scenarios:

Performing maintenance tasks on cluster infrastructure

Make changes to the configuration of the cluster services, or to infrastructure used by the cluster services, such as storage or networking. This involves putting the whole cluster into maintenance mode and stopping the cluster services on all nodes at once, but not rebooting any nodes.

Performing maintenance tasks on cluster nodes

Make changes to the cluster nodes, such as hardware, software or firmware updates. This involves putting a node into standby mode and stopping the cluster services on just that node, then rebooting if required.

(This article) Performing maintenance tasks on cluster resources

Manually manage applications or services without interference from the cluster. This involves putting one or more resources into maintenance mode so you can temporarily manage them manually.

Specific tasks

These articles describe specific maintenance or administration tasks:

Changing the Configuration of SBD

This article describes different ways to update the configuration of SBD for node fencing. Most of these tasks require stopping the cluster services, and might also require cluster maintenance mode.