Managing Nodes With the Web UI

Adding Nodes to a Cluster

Use the Cockpit HA Cluster Management web UI to add nodes to a cluster.

The following procedure assumes that Pacemaker and Corosync have been configured on the node that's being added to the cluster, and that the hacluster user credentials have been authenticated for the node.

Steps

To add a node to a cluster in the HA Cluster Management web UI, perform the following steps:

In the Cockpit navigation pane, select HA Cluster Management .
The Clusters page appears.
In the Clusters page, select the cluster you're configuring.
A tabbed page displaying the cluster information appears, initially with the Overview tab active.
Select the Nodes tab.
The Nodes tab becomes active.
Select Add Node.
The first page of the Add Node workflow appears.
Specify the name of the node to add to the cluster, and then select Next.
A message appears to confirm the node is prepared and ready to be added to the cluster.
Select Next to acknowledge the message and continue to the next step in the workflow.
The Specify node addresses page is displayed.
In the Specify node addresses page, you can enter multiple addresses for the node if the cluster uses multiple links. Select Next.
The Configure sbd page is appears.
In the Configure sbd page, configure any Storage Based Death devices (also called STONITH block devices) that have been set up, and select Next.
The Review settings page is appears.
Review the settings you have selected in the preceding steps and select Add node.
The final page of the workflow appears with a message that confirms the node has been added successfully.
Select Start node and close to start the node and complete the workflow. Alternatively, select Close to complete the workflow without starting the node.

Note:

If you plan to enable the cluster and pacemaker services on the node so they start automatically at boot time, you need to do this at the command prompt. See Creating the Cluster for more information on how to do this.

Removing Nodes from a Cluster

Use the Cockpit HA Cluster Management web UI to remove nodes from a cluster.

Steps

To shut down and remove a node from a cluster in the HA Cluster Management web UI, perform the following steps:

In the Cockpit navigation pane, select HA Cluster Management .
The Clusters page appears.
In the Clusters page, select the cluster you're configuring.
A tabbed page displaying the cluster information appears, initially with the Overview tab active.
Select the Nodes tab.
The Nodes tab becomes active.
Select the node you're planning to remove from the cluster.
A node information panel, with details of resources and services running the node, appears.
In the panel, select the Actions button.
A menu of actions appears.
Select Remove from the list of actions, and in the confirmation message that appears, select Remove to confirm the action.
A message appears and confirms the task has been completed successfully.

Stopping and Starting Nodes

Stop and start cluster nodes in the Cockpit HA Cluster Management web UI application.

Stopping a node in the web UI stops the pacemaker and corosync services on that node. Conversely, starting a node in the web UI starts those services.

The example procedure that follows assumes you intend to stop a running node and then start it again.

Steps

To stop and start a node in the HA Cluster Management web UI application, perform the following steps:

In the Cockpit navigation pane, select HA Cluster Management .
The Clusters page appears.
In the Clusters page, select the cluster whose node you're planning to stop.
A tabbed page displaying the cluster information appears, initially with the Overview tab active.
Select the Nodes tab.
The Nodes tab becomes active.
Select the node that's to be stopped.
A node information panel, with details of resources and services running the node, appears.
Select Stop, and in the confirmation message that follows, select Stop to confirm the action.
A message appears and confirms the node has been stopped. The node status is shown as Offline.
To start the node again, select Start, and in the confirmation message that follows, select Start to confirm the action.
A message appears and confirms the node has been started. The node status is shown as Online.

Putting Nodes into Standby Mode

Use the Cockpit HA Cluster Management web UI application to move nodes into and out of standby mode.

Putting a node in standby moves resources away from that node. The following procedure shows you how to use the web UI put a node into standby mode, and how you might optionally take it out of standby mode when required.

Steps

To put a node into standby mode using the HA Cluster Management web UI, perform the following steps:

In the Cockpit navigation pane, select HA Cluster Management .
The Clusters page appears.
In the Clusters page, select the cluster you're configuring.
A tabbed page displaying the cluster information appears, initially with the Overview tab active.
Select the Nodes tab.
The Nodes tab becomes active.
Select the node you're planning to put into standby mode.
A node information panel, with details of resources and services running the node, appears.
In the panel, select the Actions button.
A menu of actions appears.
Select Standby from the list of actions, and in the confirmation message that appears, select Standby to confirm the action.
A message appears and confirms the task has been completed successfully. The node status is updated to Standby.
Optionally, you can take the node out of standby mode by selecting Unstandby option that now appears in the Actions menu.

Putting Nodes into Maintenance Mode

Use the Cockpit HA Cluster Management web UI application to move nodes into and out of standby mode.

Putting a node in maintenance puts the resources hosted on the node into an unmanaged state. Unmanaged resources are not stopped or started by the cluster.

The following procedure shows you how to use the web UI put a node into maintenance mode, and how take it out of maintenance mode when required.

Steps

To put a node into maintenance mode using the HA Cluster Management web UI, perform the following steps:

In the Cockpit navigation pane, select HA Cluster Management .
The Clusters page appears.
In the Clusters page, select the cluster you're configuring.
A tabbed page displaying the cluster information appears, initially with the Overview tab active.
Select the Nodes tab.
The Nodes tab becomes active.
Select the node you're planning to put into maintenance mode.
A node information panel, with details of resources and services running the node, appears.
In the panel, select the Actions button.
A menu of actions appears.
Select Maintenance from the list of actions, and in the confirmation message that appears, select Maintenance to confirm the action.
- A message appears and confirms the task has been completed successfully.
- The Pacemaker section in the node information panel shows the status to be set to Maintenance.
- Any resources running on the node are shown as Unmanaged
When you have completed maintenance tasks, you can take the node out of maintenance mode and by the selecting Unmaintenace option that now appears in the Actions menu.