Moving from Windows Server 2012 to Windows Server 2012 R2 is fairly straightforward. Here are some tips to make sure the process goes smoothly.
If you're like me, you may prefer to be latest and greatest in some IT situations. What really gets me are those occasional situations where I want to deploy something new but have to wait a few weeks or longer for full support. With later versions of Windows Server, you may have noticed that there is an upgrade feature that comes with the server operating system. I recently ran the upgrade on a production application (I did a full image backup first!) and found the Windows Server 2012 R2 upgrade process quite easy.
One of the good things about Windows Server is that you can now natively mount .ISO files in the operating system. This particular system was a virtual machine, and there have been nice mechanisms to mount .ISO files for a while. But now it's simply a right-click inside the guest operating system. The upgrade starts from the setup process on the .ISO and running the setup.exe file, so you'll want to make sure that the drive letter doesn't change. Mounting the image as a physical optical drive or from the virtualization platform are good additional steps.
There are a few options to consider. One is to check for updates to the installer. Given that Windows Server 2012 R2 code was finalized in August 2013 with the release to market (RTM) edition, there are surely some small tweaks that may need to be corrected. So I think checking for updates is a good idea. The first option you will get on the setup is to check for these updates, then whether to do an upgrade or a new install. If you are going to do a new install, it's advisable to use a new system image unless you have a data volume you plan to hand off directly to the newly installed system. Figure A shows the option to do the upgrade on an existing Windows Server.
It is recommended that you perform the upgrade directly connected to the console, either KVM or a virtual machine console. The system reboots a number of times, and that will help you ensure that the process is going as expected. The boot menu offers a one-time option to roll back the update. With luck, you won't need it, but it's there in case something doesn't go as expected. Once the upgrade process starts, you'll see a progress bar and a few reboots, as shown in Figure B.
There are plenty of scenarios to consider. Be sure to check TechNet post 303416. This KB article outlines a lot of considerations for the upgrade, including what is and is not a supported upgrade path. For instance, you can't change editions during the upgrade, such as from Standard to Datacenter. Further, you can't come from an older operating system that was only x86 compatible to the current offering, which is x64 only. Most important, you need to use the same type of product in terms of licensing configuration for the upgrade. For example, if you downloaded a trial of Windows Server 2012 (the 180-day evaluation), you can't use your corporate licensing .ISOs and keys to correctly do the upgrade. It may work, but trust me: It's not correct.
When the upgrade process is complete, check the newly upgraded Windows Server 2012 R2 Server to make sure everything is functioning as expected. For starters, look to see whether the network configuration changed. Was a new interface assigned and was the DNS information removed? Did Group Policy and Domain Membership apply successfully? A thorough checkout before calling the upgrade a success would be a wise thing to do!
Have you taken the plunge with Windows Server 2012 R2 and used the upgrade feature? Share your tips below.