Here list several general best practices and configuration considerations for patch upgrade:
- The NDU framework was originally created to handle OneFS upgrades. The same framework is also used for the patch system and to deploy firmware packages. As designed for the 8.0 and later releases, the NDU framework can only be used to perform one action at a time. This means that once a OneFS upgrade has been started, NDU will not be available to deploy patches or firmware packages until the upgrade has been committed.
- Beginning with the 8.0 release, the NDU framework creates the possibility to upgrade a cluster and then roll back to the previously installed version anytime before the new version is committed. This is accomplished by creating a rollback image from one node in the cluster and then deploying that rollback image to all the nodes during the rollback operation. When the rollback file is created, it will include any patches installed on the node and the local patch databases. If the OneFS upgrade is rolled back, the exact patches that were previously installed on each node will be replaced with the patches contained in the rollback file. This will only be an issue if there is a different patch set installed on different nodes in the cluster. Dell Technologies recommends that you use consistent patch among all the PowerScale nodes in the cluster.
- Dell Technologies recommends that you install the patch during an off-hours maintenance window to minimize the disruption of service to clients.