Move and Decommission
You have the option to replace worker nodes with new operating system and move master nodes to hosts wth new operating system when operating teams either do not have access to the operating system or have not followed the best practices when setting up the HDP directory structures.
This option should be used in smaller clusters (under 25 nodes), where operational teams may not have access to operating system and configuration management automation tooling or have not yet followed best practices when setting up the HDP directory structures (such as ensuring HDP component data and metadata are not stored on the root volume).
This option involves decommissioning worker nodes and replacing them with worker nodes that have the new operating system version on them. For master nodes, the move-master operation is used to move all masters off of a host, and on to a new host with the new operating system version on them. Decommissioning worker nodes can take a great deal of time, depending on the density of the nodes, and move-master operations require many cluster services to be restarted, so this is a time-consuming process that requires multiple periods downtime, but it does not require any operating system level operations to be performed.