I have a very simple environment. No Sox, PCI, HIPAA, etc. I have 1 Redhat LInux Enterprise (x64) server running version 7.1. I have 18 or 19 users that need access. We use putty and samba to connect our users. We have root and 1 other account for local admininstration, but all other users rely on Centrify. Yes, the domain name will change.
This looks simple enough. I am not sure how you're doing the Samba integration, but note my comment from above (we no longer ship a recompiled version of Samba).
I have version adinfo (CentrifyDC 5.1.1-831) installed currently. Can I just run yum update?
Good timing, this version is set to EOL in July. I don't think you'll be able to upgrade in place. Work these scenarios in your lab testing.
If I remember correctly (about 5 years ago) when you run install-express.sh it prompts for the domain you want to join and the OU path.
The behavior of install-express.sh is the same.
What will happen if I upgrade or run Centrify again? Will prompt for both domains?
If you run install-express.sh, it will tell you if it can (or can't) upgrade in place.
Note - you can only be joined to ONE domain at a time. This is how Active Directory operates.
Caveat-emptor: I know you're asking all these questions to research/due-diligence. Please don't just take my answers and jump into a production setup. These answers are no substitute to real work in a lab setting.
I'm trying to do this without breaking the domain I'm currently on.
You will definitely break the trust relationship between the existing domain to join the other one. That's one of the reasons why trusts exist in the first place, to facilitate merges, acquisitions and migrations.
Good luck!!!!