The year 2012 saw one of the biggest platform and system management releases from Microsoft Windows Server 2012 and System Center 2012. The new face of IT and new expectations and requirements from customers made Microsoft develop a mature product in Windows Server 2012, with an objective to "cloud-optimize IT." There were notable advancements made in the hypervisor's third release, Hyper-V 3.0, and the virtualization stack.
Windows Server 2012 was focused not only on virtualization and cloud aspects, but also on improvement of other OS aspects and their integration with Hyper-V, Azure, and VDI. Here are the names of a few important ones: dynamic memory management and smart paging, domain controller cloning, automation with PowerShell 3.0, SMB 3.0 with a Scale-Out File Server over the cluster shared volume (which has found many use cases), Storage Spaces, data deduplication, VHDX, IPAM, NIC teaming, Hyper-V Extensible Switch, Hyper-V Replica (MS's answer to VMware's SRM), and so on.
Windows Server 2012 and Hyper-V Server 2012 swept the market. However, there were still some missing pieces in the puzzle. Windows Server 2012 R2 (Release 2.0) was released in October 2013, with some key improvements to Hyper-V and other aspects. For starters, R2 brought back the forgotten Start button to the Metro UI. There were also significant improvements from the networking and storage perspectives:
Networking: With a clear focus and vision for Cloud OS, Microsoft has worked hard towards improvement in this division. New PowerShell cmdlets have been included for Windows networking roles for better automation and control. Windows Azure has progressed from being just a PaaS provider to an IaaS as well. Windows Server 2012 introduced the capabilities of hosting a multi-tenant cloud. With R2, Microsoft took network virtualization further. Windows Azure Pack for Windows Server and System Center 2012 R2 Virtual Machine Manager provide virtual network creation and management.
Storage: Microsoft has been focused in order to provide better manageability and control over storage options for admins. Many noteworthy features were brought in with Windows Server 2012, namely SMI-S, data deduplication, Storage Spaces, iSCSI Target Server, and DFSR enhancements. In R2, we saw classic improvements to the former listed features. Data deduplication is now supported on CSV and proves to be a boon for VDI setups. Storage Spaces allows storage tiers, which facilitate movement of data between faster or slower media, based on the frequency at which the data is accessed. Moreover, the old and reliable replication engine, FRS, along with the VDS provider has been deprecated.