Upgrading Zammad 3.6.0/Debian 9-Stretch to Zammad 5.0/Debian 10-Buster

[MR74]

Infos:

• Used Zammad version: 3.6.0
• Used Zammad installation type: package
• Operating system: Debian 9 Stretch
• Browser + version: Chrome 95.x

Expected behavior:

Clean package upgrade zammad 3.6.0/debian 9 to zammad 5.0/debian 10

Actual behavior:

What things to check before upgrading the whole system ?
Need a little advise before starting …

Steps to reproduce the behavior:

Is this the right way?

• Backup the complete system
• Upgrading debian 9 to latest debian 9
• Upgrading zammad
• Debian dist-upgrade

[MrGeneration]

You may want to have 4.0 or 4.1 as step in between on your upgrade path. Just for safety.
Please also ensure that your postgresql is high enough (version wise, see: Software — Zammad documentation).

Apart from that:
Regarding your dist-upgrade:

• disable and stop Zammad before you do that
• ensure to have a backup (of course you’ll do! )
• check if the dist upgrade also affects your database server - if so, ensure to have a clean data migration in between those versions

after dist-upgrade, please ensure:

• to update your Zammad repository to the debian 10 version (see Install from package — Zammad documentation ) - remove the old repo version (this is crucial)
• reinstall Zammad from the new debian 10 repo

Please note that Zammad packages are distribution and version specific.
Skipping above mentioned step will cause you ending in a non functional Zammad installation.

Other than that you should be fine.