As operating systems evolve and become increasingly sophisticated, demands on a server's computing resources also increase. So any software upgrade cycle -- especially with critical enterprise operating systems -- must include evaluating the server's hardware to ensure adequate resources that preserve required performance levels.
Evaluation can uncover potential system resource shortages that can be resolved with workload
balancing, system upgrades, additional server deployments or other strategies. This tip examines
Microsoft Windows Server 2012 R2 requirements.
Minimum Windows Server 2012 R2 requirements
The minimum system requirements to support
Remember: These requirements are for a minimal OS deployment only -- a system that is configured or provisioned to provide only these resources will be unable to run any applications or virtual machines on top of the OS. This means installing Windows Server 2012 R2 on a machine that meets minimum requirements has little practical value, other than to give IT professionals experience with installation techniques and familiarity with the user interface.
When moving from a simple test or evaluation deployment toward a practical Windows Server 2012 R2 install, it's important to provide additional system resources to meet the added requirements of the particular role and application.
Requirements for Windows Server R2 roles
Windows Server 2012 R2 can provide an enormous number of services and capabilities that specific server roles use -- but these might not be installed in a minimum configuration. Organizations will need to allocate more memory, disk space and processor capabilities, in addition to the minimum requirements, depending on the new server's intended role.
More on Windows Server 2012 R2 requirements and features:
Updates in Windows Server 2012 expected to focus on agility, the cloud
Q&A: Microsoft's Brad Anderson talks Windows Server 2012 R2 and BYOD management
Generation two virtual machines: A new Windows Server 2012 R2 Hyper-V feature
Consider an application server role. The application server must provide a suite of additional services, including Internet Information Services (IIS), Microsoft .NET Framework, ASP.NET, COM+, Message Queuing and so on. Each service will increase the amount of processor work, memory space and storage the server requires.
A role like remote desktop services (RDS) involves numerous additional services; RD virtualization host, RD session host, RD connection broker and RD Web access must be installed with the server -- and each will impact processor, memory and storage needs. If RemoteFX virtualized graphics processing unit (GPU) is added to accelerate Windows client virtual desktops, the server will require processors that support second-level address translation (SLAT) and at least one GPU that supports RemoteFX and DirectX 11.
As another example, the Hyper-V role allows the server to support virtualization and host multiple workloads simultaneously. This requires additional memory and storage for Hyper-V components, processors with hardware-assisted virtualization such as Intel-VT or AMD-V, along with hardware-enforced data execution prevention invoked through the Intel execute disable or AMD no execute (NX) bit in system BIOS. Although current enterprise-class processors provide virtualization extensions in the processor, it's still important to verify those capabilities before attempting a deployment.
Computing requirements don't stop with the OS and its services. Additional resources must be allocated to support the actual enterprise application such as Microsoft BizTalk, Microsoft SQL or any number of enterprise resource planning or customer relationship management platforms. Applications require processor capacity, memory space, storage and network I/O beyond the needs of the underlying operating system, so check a particular application's requirements, and add those demands to the OS.
Workload and resource planning becomes even more complicated when the Windows server is virtualized. During virtualization, computing demands of each VM will multiply processor, memory, storage and networking requirements.
Suppose a typical server OS and application require a processor core, 10 GB of RAM and 50 GB of storage. Hosting 10 such virtual machines would need approximately 10 times those resources on the server (about 10 processor cores, 100 GB of RAM and 500 GB of storage). The exact amount of resources will vary with server roles and individual application demands.
It is impractical to list specific system requirements for every possible combination of server role and application. The best approach for resource planning is to use systems management tools to benchmark the resource usage of actual Windows Server 2012 R2 roles and applications to estimate resource needs on another server. Benchmarking can also help IT pros evaluate and optimize Microsoft Windows Server 2012 R2 performance.
This was first published in September 2013