Hello,
I am new to Zammad and to my current company. Unfortunately there is an old version 2.2 of Zammad running there.
How is the correct way to update version 2.2 (on Centos 7) to version 3.4?
It does not work via the repo because the database is not completely updated.
Are there any old RPM packages so that I can pull it up piece by piece? Or will only work from the source?
in theory™ you can upgrade Zammad (via package installation) from any previous version.
In some cases you ma have to run zammad run rake db:migrate once (or twice) more.
If this still fails, this problem proberbly is based on the configuration of your Zammad and thus leaves unsolvable issues for a automated migration. However: The tracebacks and console commands should give you hints about that.
These information are required to be able to help you better.
Especially Zammad 2.5 or 2.6 had migrations that could affect “broken configurations”.