Manage Software Updates

Updates (also known as patches) to the system software become available as needed to address issues associated with a current StarlingX software release. Software updates must be uploaded to the active controller and applied to all required hosts in the cluster.


Updating Distributed Cloud is distinct from updating other StarlingX configurations.

The following elements form part of the software update environment:

Reboot-Required Software Updates

Reboot-required updates are typically major updates that require hosts to be locked during the update process and rebooted to complete the process.


When a StarlingX host is locked and rebooted for updates, the hosted application pods are re-located to an alternate host in order to minimize the impact to the hosted application service.

In-Service Software Updates

In-service (reboot-not-required), software updates are updates that do not require the locking and rebooting of hosts. The required StarlingX software is updated and any required StarlingX processes are re-started. Hosted applications pods and services are completely unaffected.

Software Update Commands

The sw-patch command is available on both active controllers. It must be run as root using sudo. It provides the user interface to process the updates, including querying the state of an update, listing affected hosts, and applying, installing, and removing updates.

Software Update Storage Area

A central storage area maintained by the update controller. Software updates are initially uploaded to the storage area and remains there until they are deleted.

Software Update Repository

A central repository of software updates associated with any updates applied to the system. This repository is used by all hosts in the cluster to identify the software updates and rollbacks required on each host.

Software Update Logs

The following logs are used to record software update activity:


This records software update agent activity on each host.


This records user actions that involve software updates, performed using either the CLI or the REST API.


This records the execution of patch scripts while in-service patches are applied.

The overall flow for installing a software update from the command line interface on a working StarlingX cluster is the following:

  1. Consult the StarlingX support personnel for details on the availability of new software updates.

  2. Download the software update from the StarlingX servers to a workstation that can reach the active controller through the OAM network.

  3. Copy the software update to the active controller using the cluster’s OAM floating IP address as the destination point.

    You can use a command such as scp to copy the software update. The software update workflows presented in this document assume that this step is complete already, that is, they assume that the software update is already available on the file system of the active controller.

  4. Upload the new software update to the storage area.

    This step makes the new software update available within the system, but does not install it to the cluster yet. For all purposes, the software update is dormant.

  5. Apply the software update.

    This step adds the updates to the repository, making it visible to all hosts in the cluster.

  6. Install the software updates on each of the affected hosts in the cluster. This can be done manually or by using upgrade orchestration. For more information, see Update Orchestration Overview.

Updating software in the system can be done using the Horizon Web interface or the command line interface on the active controller. When using Horizon you upload the software update directly from your workstation using a file browser window provided by the software update upload facility.

A special case occurs during the initial provisioning of a cluster when you want to update controller-0 before the system software is configured. This can only be done from the command line interface. See Install Software Updates Before Initial Commissioning for details.