Considerations for Server OS Upgrade (Win2012R2 to 2019) hosting SQL Server?

Solution 1:

I did this nearly a year ago, the only thing I did, was first to create a Backup then update the SQL to the latest and installed any versions between 2012 and 2019, some Windows updates may be required to upgrade to the next, but it was running Smoothly and fine.

REMIND Backing up!! (Shutdown and take there, no online snapshot due to the Consistency)

Work steps

• update the SQL Server
• Stop & Shutdown SQL Service.
• in place upgrade to 2016 + all Windows updates
• in place upgrade to 2019 + all Windows updates

For All Action should be planned from starting till end depending on size Around 1-2Days. (In my Action it was required 3 days from first to last step)

The Server is now working since then without any error.

It is Possible, but official supported, to upgrade from 2012 to R2 and start forward to the in place upgrades till 2019.

Conclusion

Remind, that, in case if it's a VM, it's mostly better to back up the Databases and replace the VM with the newest OS and SQL if possible via a Fresh Installation. Mostly it takes less time.