June 20, 2022 at 6:46 am
i have a task:
Uninstall SQL 2012
Install SQL 2019
use the existing AOG Listener & cluster name
Can any one guide step by step?
June 21, 2022 at 7:10 am
Thanks for posting your issue and hopefully someone will answer soon.
This is an automated bump to increase visibility of your question.
June 24, 2022 at 6:49 pm
The short answer is, yes this can be done. However if you look at Business Risk it is hard to work out anything with a much higher risk. It is far safer to build a new cluster and migrate to it. Your current plan will leave you with a window with no working SQL, and if the new install fails you could remain with no SQL for a few days while you build some new servers. You also have no way to test the process until you do it for real, and no way to revert to the old SQL version if it all fails.
It is far safer to build a new Windows cluster and install a new SQL cluster on it. You can test the migration process, find out what has been missed out of your plan (some things will be missed!) and retry until it all works.
If you are concerned about changes to connection strings due to changing the cluster name then you need to use DNS aliases. The best way is to change all your connection strings to use a DNS alias, and set the alias to point to the old server. The target of the alias can be changed at cutover time to point to the new cluster. If your post-cutover testing fails then repoint the alias to point to the old cluster. This breaks the link between physical and logical server names and sets you up for future migrations. It also really lowers Business Risk.
The cheap and nasty way is to leave your connection strings as they are. At cutover time shut down your old servers and evict them from the domain. Create a DNS alias with the same name as the old cluster and point it to the new cluster name. The applications will neither know or care they now connect via an alias. Fall back becomes more complicated, you have to delete the alias and re-join the old servers to the domain. Good luck with that, this approach went over my Business Risk red line some time ago.
Original author: https://github.com/SQL-FineBuild/Common/wiki/ 1-click install and best practice configuration of SQL Server 2019, 2017 2016, 2014, 2012, 2008 R2, 2008 and 2005.
When I give food to the poor they call me a saint. When I ask why they are poor they call me a communist - Archbishop Hélder Câmara
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