The process to patch Exadata stack and software changed in the last years and it became easier. Now, with patchmgr to be used for all (database servers, storage cells, and switches) the process is much easier to control the steps. Here I will show the steps that are involved in this process.
Independent if it is ZDLRA or Exadata, the process for Engineering System is the same. So, this post can be used as a guide for the Exadata patch apply as well. In 2018 I already made a similar process about how to patch/upgrade Exadata to 18c (you can access here) and even made a partial/incomplete post for 12c in 2015.
The process will be very similar and can be done in rolling and non-rolling mode. In the first, the services continue to run and you don’t need to shutdown databases, but will take more time because the patchmgr applies server by server. At the second, you need to shutdown the entire GI and the patch is applied in parallel and will be faster.