Hi all,
We have two environments of Vertica 7.1.1-10, 10 node each, database of 40TB, K-safety 1.
One as the production and the other is DR.
We want to close the DR site and merge the two clusters to one 20 nodes production cluster.
Several questions:
1. Do I need to uninstall Vertica from the DR site before I'm adding the nodes to the production site? or I need only to drop the existing database on the DR site?
2. How it's work with the downtime when I'm adding the nodes? There will be downtime? Can I still work with the production environment while I'm adding the nodes (at the re-balancing time)?
3. Can I add 10 nodes together? or I need to add them in batches, 5 nodes each time for example?
4. What is the overhead on the system?
5. How can I determent the re-balancing time?
If you have any more insights and things that I need to check or to give more attention... I'd love to hear 
Thanks 
Chen