how to upgrade Veeam related server

[apolloxm]

We had Veeam Backup &Replication, Veeam Enterprise Manager, Veeam ONE. most of them are running in Windows Server 2016. We are planning to migrate Windows server 2016 to Windows Server 2022 or Windows Server 2025.

We installed the Veeam Backup and Replication, Veeam Enterprise Manager in one VM which installed Windows Server 2016 name as Server A
There is another Physical Server named as Server B with ICSCI with Windows Server 2022 as Backup Repository Server
Veeam ONE was installed in Server C which was a VM which installed Windows Server 2016.

Here is my questions.
1. Should I migrate windows Server 2016 to Windows Server 2022 as I have seen that the Windows Server 2025 had a high CPU and RAM issue posted
veeam-backup-replication-f2/server-2022 ... 2-210.html

2. Does they have any sequence? for example should I migrate Veeam ONE firstly then Veeam Enterprise Manager then VBR?

3. Do you have any article that I can follow up? For the https://www.veeam.com/kb1889 as mentioned below, We are using Version 12.3 for Veeam Backup Enterprise Manager. Do we still need to contact Veeam Support for assistance with clearing the email client settings in the configuration database?

Support Assistance Required to Complete Migration
When migrating the Veeam Backup Enterprise Manager deployment from one machine to another and using version 12.x (12.0, 12.1, or 12.2) consider the following:

For Veeam Backup Enterprise Manager versions 12.0 and 12.2, if the mail server settings are configured, you must contact Veeam Support after completing the migration steps in this article for assistance with clearing the email client settings in the configuration database (reference Issue ID# 614693).
For Veeam Backup Enterprise Manager version 12.1, you must either contact Veeam Support before migration for specific steps and database modifications that must occur or upgrade to the latest version of Veeam Backup Enterprise Manager (12.2 at the time of writing) and review the prior bullet point.

[Mildur]

Hi Apollo,

May I ask if you’ve considered migrating to the new Veeam Software Appliance and Veeam Infrastructure Appliances instead of updating to newer Windows Server builds?
Using our appliances would offer several benefits:
- A pre-hardened backup environment
- Immutable backups
- Automatic security and product updates through Veeam Updater
- Cost savings by avoiding the need for Windows Server 2025 licenses

To address your questions regarding your existing environment:
1.) If you have the hardware available, consider migrating your backup repository to a Veeam Hardened Repository. It’s more stable than ReFS and supports immutable backups. And I wouldn't trust a OS in-place upgrade with reFS right now with the reports we are seeing in that forum topic.
2.) For OS upgrades, the order doesn’t matter. For Veeam product updates, follow this sequence: Veeam ONE → Veeam Enterprise Manager → Veeam Backup & Replication.
3.) Yes, that still applies if you’re running one of the mentioned version numbers. But I assume you are already on v12.3.2

Best,
Fabian