Configuring Fencing in the Web UI

You can use the web UI to configure different kinds of fencing configurations.

The configuration options that become available in the UI depend on the fencing type you create. For example, if you configure SBD fencing for a cluster, the web UI might present different options to those you see when you configure IPMI LAN fencing.

For the purposes of providing an overview of configuring fencing, the following sections show you how to configure SDB fencing in a cluster. The examples assume you have completed the steps discussed in SBD Fencing.

Creating a Fencing Device

Use the Cockpit HA Cluster Management web UI to create a fencing device for a cluster. For the purposes of the example, the procedure steps shown are those for creating device for SDB fencing.

What do you need?

The steps in the following procedure assume you have completed the following:

• Configured a shared storage device to be accessible from all nodes that in the HA cluster. A shared storage device is needed for cluster service and application messaging, and for cluster SBD fencing.

• Completed the steps discussed in SBD Fencing.

Steps

To create a fencing device using the HA Cluster Management web UI application, perform the following steps:

1. In the Cockpit navigation pane, select HA Cluster Management.
   The Clusters page appears.
2. In the Clusters page, select the cluster you're configuring.
   A tabbed page displaying the cluster information appears, initially with the Overview tab active.
3. Select the Fence devices tab.
   The Fence devices tab becomes active.
4. In the Fence devices page, select Create Fence Device.
   The first page of the workflow for creating fence devices appears.
5. Specify a name for the device you're creating, and from the Fence device type list, select fence_sbd for the purposes of this example.
   The Instance attributes page appears.
6. In the devices field, enter the path to the shared storage device that's been set up for the SBD fencing.

   Use a persistent device path, for example a link within the /dev/disk/by-id/ directory system in the following format:

   /dev/disk/by-id/wwn-0x6d401fd54x2...44b8040d88087Z4

   Optionally, you can use the use the search box and the More attributes filter to display other properties you might want to set for the device. You can also do this later, after you have created the device, as discussed in Configuring Fence Device Arguments.

   The Settings page appears.
7. On the Settings page, select Start automatically (the preselected default) or Disabled, depending upon whether you want the device to be started after it's created.
   The Review new fence device configuration page appears.
8. Select Create fence device.
   A message confirming the device has been created appears. Upon acknowledging the message, the workflow closes, and the Fence devices page appears with the newly created device listed.

Configuring Fence Device Arguments

Use the Cockpit HA Cluster Management web UI to configure parameters for a fencing device.

What do you need?

• The following proedure assumes you have created a fencing device for the cluster.

• For more information on creating fencing devices, see About Fencing Configuration (stonith) and Creating a Fencing Device.

Configuring arguments for a fencing device is a task for advance use cases, and the precise configuration required depends upoon the cluster environment, the device hardware, and so on.

The following table gives an overview of some file device arguments you can set in the HA Cluster Management web UI:

Note:

The properties available in the UI can vary depending upon the type of fencing device you're configuring.

Property	Default	Overview
pcmk_reboot_timeout	60s	Advanced use only. Specifies a device-specific timeout value to use for reboot actions instead of that specified by stonith-timeout.
pcmk_off_timeout	60s	Advanced use only. Specifies a device-specific timeout value to use for off actions instead of that specified by stonith-timeout.
pcmk_reboot_retries	2	Advanced use only. The maximum number of times to retry the reboot command within the timeout period.
pcmk_status_retries	2	Advanced use only. The maximum number of times to try the status command within the timeout period.

Steps

To configure the arguments for a fencing device in the HA Cluster Management web UI application, perform the following steps:

1. In the Cockpit navigation pane, select HA Cluster Management.
   The Clusters page appears.
2. In the Clusters page, select the cluster you're configuring.
   A tabbed page displaying the cluster information appears, initially with the Overview tab active.
3. Select the Fence devices tab.
   The Fence devices tab becomes active.
4. In the Fence devices page, select the fence device you're configuring.
   A panel with an overview of the selected fence device appears.
5. Select Arguments.
   The panel shows a selection of arguments that can be configured for the device. The panel contains search box and filter to control items the list includes.

   Tip:

   Select the information icon that follows each property to display information about role and function of that property.

6. Select Edit Arguments
   The Edit fence device arguments page appears.
7. Use the search box and the filter to display the arguments you need to configure, and set the values as required. Select Save arguments.
   A message confirming the successful update of the parameters appears. Upon acknowledging the message the workflow closes and the Fence devices page appears.