There is no problem to have two ePo servers in you environment.
I would suggest to double check whether you have any automatic tasks that are deploying the agent from your old ePO. if there are stop them in order to prevent moving systems between ePO servers.
You dont need to uninstall the old agent you can install the agent from the new ePO over the existing one.
Additional you could use this article for migration of the systems between your new ePO and the old one, McAfee Corporate KB - How to transfer/move computers from one ePolicy Orchestrator server to another KB79283
hi fmolinari88, there are many options you can take.
Option - A: Setup and install ePO with new database at new cluster. Register each server and "transfer" your systems/policies/tasks everything. The new server can be 5.9.0. Here's a quick plan of action:
1. Install ePO 5.9.0 on new server
2. Register each other ePO servers (both 5.3 and 5.9.0). Exchange security keys.
3. You can now enable system/policy/task sharing and start the transfer process.
4. Monitor progress and continue the migration.
5. When everything (all systems, tasks, policies etc) has been transferred and clients are communicating successfully, you can focus on the new server.
DON'T turn off the old server just yet. Give it a little time to see if there's anything that's still trying to communicate to the old server. Or you may discover something... just leave it running for a little while.
This approach is a little lengthy but works well.
Option - B:
1. Upgrade the current 5.3 to 5.9 on the SAME server.
2. Setup the NEW 5.9 epo server. When you install, ePO will point to a blank database.
3. Now that BOTH servers are running 5.9 you can IMPORT the database on the NEW server, then turn off the old one. Be sure to use same dns name, ip address and everything for least disruption.