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.

Figure A

 

 

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.

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!

Other tips?

Have you taken the plunge with Windows Server 2012 R2 and
used the upgrade feature? Share your tips below.