Upgrading the cluster’s underlying OS

Operating system requirements

Only RHEL7, CentOS7.7, and Ubuntu 18 operating systems are supported with the HDP intermediate bits and Ambari 7.1.x.x. Ensure that all your hosts in the cluster are on the supported operating system before starting the upgrade from HDP 3.1.5 to HDP intermediate bits.

For many, this is a process that takes time and orchestration between multiple teams within your organization. Two high-level guidelines for moving from one major operating system version to another is as follows:

In-Place and Restore:

Perform an In-place OS refresh and use Ambari Restore Host feature

Move and Decom:

Move Masters and Decom/Recom Workers

Each option has advantages and disadvantages and high-level decision criteria.