I'm planning an upgrade of a servergroup from 8.1 to 9.1 and I'm not entirely clear on the proper way to do it.
I'd like to do an "in-place" upgrade, meaning there will be a downtime during which the environment won't be available to users and the existing environment will be upgraded.
My questions are less about the details of which steps to take to prepare the environment, etc. Those are covered in the documentation and I think I'm OK on that side. My questions are more regarding the order in which to do things in the servergroup, which servers to turn off or on at what time, etc.
Let's say you have 3 ARServers in the environment, running as a servergroup.
Server A is ranked as number 1 for all tasks, Server B as 2 and Server C as 3.
The environment has these modules installed on it: ARServer, Atrium CMDB, Atrium Integrator, ITSM Incident/Problem/Change/Asset/Knowledge, Smart-IT, SRM, SLM, Process Designer.
I think the first step would be to stop servers B and C and only have A running, right?
Then I'd upgrade the full stack of modules on Server A, one after the other, in the order described here.
Once Server A is upgraded and running fine, how do I go about server B? Should I stop the Remedy services on server A first? Or should server A be up and running while upgrading B?
The documentation on this topic is not entirely clear on that part.
In the first bullet-point, it says: "In your production enviornment if you have removed the primary server from the server group before you upgrade..."
Why would I remove the primary server from the servergroup in the first place? I mean, it says "if", so I assume it's optional, but then why would you START your instructions with such an optional route? Why not start the documentation with the normal way to do it and THEN cover the special cases? (Or am I understanding it wrong?)
Then it says: "Run the installers on the secondary server, without starting the existing BMC Remedy AR System server."
Does this mean I should just have server B up and running while upgrading it, while servers A and C are off?
If so, then I think it kind of contradicts another part of the documentation, where it says:
"To install Atrium Integrator server on the secondary server:
1. Stop all the members of the server group except for the primary server and the one on which you want to install Atrium Integrator server..."
Granted, this is from the INSTALLATION instructions of AI, not from the UPGRADE instructions, but then again the upgrade instructions don't mention servergroups at all, so I thought I'd hold on to what I could find.
It would be nice to get some clarification on that. My instinct and past experience would tell me to simply leave server A up and running while upgrading server B. Once B is done, shut B off and start up C (while still leaving A up and running).
I wouldn't even change the server group ranking entries.
Thanks in advance for your input.