Myself being new to PAM, I am going through lots of configurations and have been documenting them for my reference but I thought I'd share it here too.
I wanted to capture all the steps required when you are on 2.8.x and want to migrate and upgrade to 3.1.1
So this article is actually 3 parts.
1. Upgrade PAM 2.8.x to 22.214.171.124
2. Migrate PAM 126.96.36.199 to 3.0.0
3. Upgrade PAM 3.0.0 to 3.0.1 3.0.2 3.0.3 and 3.1.1 (Now that 3.0.3 is available, that would be the upgrade path)
Between Step 2 and 3, you get to add a 2nd HDD for the migration and also discard it after completing the upgrade.
Here are the links to the articles.
I hope you find it useful.
Revision1: Upgrade will be going from 3.0.0 to 3.0.2 instead of 3.0.1, to avoid known issues.