With the End of Support for Windows Server 2008 on January 14th, 2020 - you no longer have the ability to receive Security Updates or Support for any servers running Windows Server 2008. If you need to keep these systems under some level of support after January 14th - you have a few limited options:
- You can migrate your Server and workload up to Azure (https://docs.microsoft.com/windows-server/get-started/modernize-windows-server-2008#migrate-to-azure) and receive up to 3 free years of Security Updates and Support from Microsoft.
- Provided you have an Enterprise Agreement / Volume License Agreement or you have purchased Software Assurance - you can enter into an Extended Support Agreement with Microsoft for up to 3 years and you will be able to register / enroll a fixed number of systems into this program.
Lets be honest - neither of these is a good LONG TERM strategy. Ultimately you need to migrate your workloads OFF of the old platform and on to a NEW platform (like Windows Server 2019). How do you go about doing that for key WORKLOADS that can't migrate up to the Cloud? I tracked down Ned Pyle, Principal Program Manager from the Windows Server Team to talk shop about the #2 Workload for servers: "Active Directory Domain Controller".
There are a lot of manual and time sensitive steps that Ned goes through in this demo - but trust me, it's not that bad when you actually get started. The main thing to remember is replication between sites and allowing information to replicate (or forcing it to speed up). The best part about this approach with integrating another DC into existing sites is that you will be introducing very little disruption to your end users in these sites - due to the multi-master architecture in use for Active Directory.
All the detailed information including a variety of caveats that could come up are documented over on Docs which can be reached at https://aka.ms/ws2008ADMigration