How to upgrade OS of SCCM Site server

Question

I have below configmgr hierarchy. I would like to upgrade OS of each site system server. I do have plan as mentioned below, Kindly provide me your thoughts for same. Thanks.

Environment:

• CAS, 2 Primary running with OS Windows Server 2012 R2
• SQL database of CAS is on different box
• SQL database of Primary is on same box
• SUP role installed on CAS and 2 Primary

My plan to upgrade OS of each site server in below sequence and using site recovery method of SCCM.

Method to use:

• Backup full SCCM site using site maintenance task. Bring new server with OS windows server 2019. Shutdown old server and delete record from AD. Rename new server same to exact the old one and join to AD. Install all pre-req. Install SQL. Restore CM_DB which was backed up and finally use SCCM site recovery method.

so query I do have:

1. can we start with CAS DB server upgrade first then CAS and finally Primary?
2. what is correct sequence to upgrade OS of each site server considering above environment?

Answer 1

I suggest to move to Server 2022 directly for longer support.

Generally you go top-down.

E.g. Upgrade CAS, then the primaries. All in all you really need to make sure that no hostnames (FQDN) change of any kind. Including the SQL Database server. Also make sure to reapply the correct permission to SQL again.