Perhaps the easiest type of cloud migration to perform is moving a workload from an on premises web server to one of the cloud providers.
It’s generally easy because there are many third party organizations that provide tools that allow you to “lift and shift” an existing website or web application into the cloud. The tools for migrating websites from IIS on Windows Server 2003 to your cloud provider of choice are often more user friendly and capable than the tools that you would use to migrate from IIS on Server 2003 to IIS on Server 2012 R2.
When migrating to the cloud you have two general options, IaaS or PaaS. IaaS is fairly straight forward – you deploy a VM to your cloud provider of choice, install IIS on that VM, then migrate the website or web application from your on-premises IIS server to the VM hosted in the cloud. This is pretty much the same process that you’d use to migrate to a Server 2012 R2 server. The drawback of this method is that you still need to do all the mucking about with the cloud hosted VM that you’d do with the on-premesis box. One of the common misconceptions about cloud hosted VMs is that the cloud provider keeps them up-to-date patch wise. The reality is that once you spin the VM up, you’re responsible for patching it. The benefit of running a VM in the cloud is that you don’t have to manage and pay for the on-premises infrastructure to host the VM.
PaaS is a different beast. With PaaS, the cloud provider basically does the IIS hosting and you deploy your website to them. The cloud provider takes care of all the security aspects of the underlying hosting platform and your website or web app runs on top of it. As I mentioned earlier, there are a bunch of third party vendors who provide tools to assist in the migration. For the most part, you’ll reduce your costs by migrating your website or web apps to a PaaS environment – because suddenly your only paying for that sliver related to hosting rather than paying for underlying OS and the staff required to manage it.
If you’ve already got the on-premises infrastructure to host a VM running Server 2012 R2 IIS or your organization has some existential issues around running critical business workloads in the cloud (there are many orgs that just don’t want to run workloads in someone else’s datacenter and it doesn’t matter what financial incentives exist, that won’t change) – then you should migrate to an on-premises solution. If you’re ready to dip your toe into the cloud (however odd that metaphor is) then seeing how existing IIS workloads run in the cloud is a good first step towards integrating the cloud into the way your organization does IT.