You would use this step to switch back to the backup version of the root file system in the  following immediate circumstances only: GLYPH<SM590000> The upgrade workflow had failed at some point. OR GLYPH<SM590000> The instance does not come up with the new level. In contrast, if problems arise later (after the workflow has already been finished) you can run  the rollback workflow to restore the previous service level. The file path for the definition file of  this workflow is as follows:  /usr/lpp/zcx_zos/workflows/rollback.xml 7.1.2 Maintenance for containers Software that runs within the containers of zCX must be serviced separately from zCX itself.  There are many sources for these containers, starting with images pulled from Docker Hub or  the proprietary registries of any vendor and continuing up to containers built by your  organization. For this reason, the procedures to install and activate service to the software of  a container might vary. Maintenance without Docker swarm Applying maintenance to a container instance normally replaces the image that is used to  start this container with a newer one.  The examples in this section show the upgrade from Grafana5.2.0-f2 to 5.2.0-f3. Grafana is a  graphical data visualizer that we use to monitor our zCX instance in Chapter 7.6, “Configuring  Grafana to monitor zCX containers” on page 168. Notice that no persistent data is used for Grafana in Example 7-3 on page 146. This approach  keeps the example simple and focused on the maintenance and not on setting up Grafana. If  you have persistent data that is defined for your Grafana container, the  docker run  command  reflects that. (For information on the use of persistent data, see Chapter 10, “Persistent data”  on page 233.) Example 7-3 Starting a Grafana container VL1:/home/admin> docker run -d -p 3000:3000 --name grafana  ibmcom/grafana-s390x:5.2.0-f2 d5bd946914840f7d8618c594f8676540b6e96b2ffacdd9598c9f0a6980897b0f To update this container to a newer level, you must pull the newer version of the Docker image  from your registry, by using the tag that points to the correct version. In Example 7-4 on  page 146, we upgrade our Grafana from the previously installed version 5.2.0-f2 to the new  version 5.2.0-f3. Example 7-4 Pull a new version of Grafana from the registry VL1:/home/admin> docker pull ibmcom/grafana-s390x:5.2.0-f3 5.2.0-f3: Pulling from ibmcom/grafana-s390x b766debbc269: Pull complete 6a13c128fd9c: Pull complete d6662734a61f: Pull complete b6c6781ca03e: Pull complete 638b1f753742: Pull complete Digest: sha256:752c2a42cec21c88c1821cd7afa9a6e593a5646ad035893adb0e03da350d2a0d Status: Downloaded newer image for ibmcom/grafana-s390x:5.2.0-f3 146  Getting started with z/OS Container Extensions