https://unknowndba.blogspot.com/2018/12/exadata-patching-patchmgr-modifyatprereq.html
https://netsoftmate.com/blog/step-by-step-exadata-compute-node-patching-18c
https://www.fernandosimon.com/blog/category/engineeredsystems/exadata
Exadata Database Machine and Exadata Storage Server Supported Versions KB153930
https://mylearn.oracle.com/ou/course/exadata-database-service-deep-dive-workshop/121072/188170
