Defining Software-Defined
At its core, a software-defined technology seeks to separate the control plane from the data plane. The easiest example here is a traditional Ethernet switch. On that switch is a logic board, full of ASICS, memory, and ultimately a piece of flash from which the kernel of the switch boots. Herein lies the control plane. That kernel is vendor-proprietary, and often times modifying the kernel via upgrades, reboots and some types of configuration changes carries the risk of interrupting end-user and server traffic. We call this the data plane.
Ok, so… what’s the big deal here? For those of you who have brought compute virtualization to your datacenters, the answer is readily apparent. Higher service availability, rapid provisioning, increased server utilization, etc. are all benefits that companies like VMware and Microsoft tout with their virtualization offerings. The underlying key here is that the features IT craves now reside in software, and are not tied to vendor-specific hardware.
So… Hardware is Dead?
Hardware isn’t dead - not by a long shot. But there is a shift happening, and part of this is the careful examination and acquisition of key hardware features that improve aspects of the software-defined datacenter. Keep in mind that core technologies aren’t going to go away. We still need servers with CPUs, switches with speeds and feeds, disks for I/O and storage. There are also a myriad of features that help to enable and enhance the software-defined datacenter. A good example might be Intel’s VT-d extensions, which enable software features such as SR-IOV. There are also vendor-specific technologies such as Cisco’s UCS VIC technology, which allows for similar advantages that SR-IOV brings. This isn’t meant as a debate as to which technology is better or more appropriate for your datacenter, but it is an example of how hardware vendors will need to innovate to survive in this software-defined world.Compute virtualization brought about a change in the way customers look at server hardware. If the core of the server is the same, vendor lock-in becomes less of a concern. Intel doesn’t give different CPUs to Dell and Cisco, so the key differentiations become what those vendors do with the hardware. How many expansion slots does this server have? How much RAM can it hold? How many disks can I put in here? What vendor-specific technologies can I take advantage of by choosing this vendor? Every customer requirement is different and it is key for customers and their partners/vendors to understand what hardware technologies can aid them in their software-defined journey.
SDS and SDN: The New Players
The new kids on the block are the two other major parts of your existing datacenter: storage and networking.Software-Defined Storage
For the purposes of this article, it might help to simplify the definition of software-defined storage. There are many products at market that can claim that they are an SDS solution, whether it is in the form of core storage, I/O acceleration or distributed caching. With this article’s focus on the mid-market sector, let us focus on something every SDDC requires: core storage.As Chuck Hollis outlined in his latest blog post, there is a new storage consumer in the marketplace. New and future administrators and architects who have cut their teeth in the industry on compute virtualization are very open to the idea of decentralized, distributed storage, and why not? These people are aware that even with virtualization, server compute resources and I/O pathways continue to be under-utilized. Thus, we head towards a strategy the industry has named hyperconvergence: the concept of a distributed architecture where each compute node contributes to the processing AND storage resources of a cluster.
Again, this model of storage does have physical components. It requires disk – some customers will prefer a mix of SSD and traditional magnetic HDD, and some will take the leap to an all-SSD tier of storage. It also requires an interconnect (data plane), which may come in the form of 1Gb Ethernet, 10Gb Ethernet, InfiniBand, etc. There is also a set of data services offered by the technology, whether it be in the form of security, protocol, data protection, caching, etc.
Each customer use case will differ, and it is critical that customer applications and performance demands are carefully considered when selecting an SDS strategy. For many customers, the introduction of VMware’s VSAN and EMC’s ScaleIO offerings will usher in an additional tier of storage. For others, this will solidify the adoption of virtualization within their datacenter, as small businesses invest in a distributed yet centrally managed storage platform that can scale and perform, without the required investment of a dedicated storage array, or the cost of tooling an administrator with storage expertise.
Software-Defined Networking
VMware’s acquisition in 2012 of Nicira piqued many people’s interest. As a “hypervisor vendor” why would they be interested in a networking product? VMware, through many of its recent offerings, wants to make it clear: we offer software-defined datacenter solutions, not just a virtualization hypervisor. Cisco is another great example of a vendor breaking its mold of “network vendor” – they are also focused in datacenter transformation, through the use of its converged technologies and its Application Centric Infrastructure, or ACI.It is important to remember that networking is not new to a vendor like VMware. Features and improvements such as Network I/O Control, Distributed Switching and vCloud Networking and Security are features customers are looking to adopt to increase performance and availability, and to ease administration. After companies realize these benefits, larger enterprises begin to recognize larger areas of concern: automation and scalability. Enter software-defined networking.
Enterprise customers looking to automate IT operations and develop catalogs and workflows will naturally look at solutions such as VMware NSX to help provision and automate virtual networking services to their consumers. The goal of SDN aligns with the goal of SDS and SDDC: run enterprise services in software against commodity hardware. SDN isn’t just overlays, it’s a complex ecosystem comprising switching, routing, security, remote access, inter-site connectivity, load-balancing, policies, etc. The messaging remains the same though: what if I can run all of these services in virtual controllers, and the only hardware I need in the middle are high-speed interconnects?
Ultimately, to justify SDN’s existence in the enterprise, it needs a problem to solve. Large-scale SDN platforms such as ACI and NSX are going to require that a company have an existing investment in a provisioning and automation tool, such as vCloud Automation Center. N-tier applications requiring fencing, firewalling or dedicated networking become automation challenges as customer private cloud environments grow. To that end, a key question arises: where does SDN fit for the mid-market?
Automation
The answer to the SDN/mid-market question lies in automation. As an organization, how much of IT operations have you automated? Many commercial customers today sit firmly in the camp of the creation of virtual machine templates, which are tied to distributed port groups with specific security and performance profiles, with virtual disks assigned to a storage profile that matches performance and capacity requirements to the appropriate datastores. The great news here is that ALL of these features are available to you with vSphere Enterprise Plus! So whether or not you believe you are automating your IT operations, chances are you have at least begun that journey.If your IT operations are expansive, and have grown to dedicated teams for networking, storage, compute and applications, automation and self-service provisioning may be in your future. In the interest of keeping this article focused on defining software-defined technologies and their fit for mid-market, I’ll avoid the tangent of private cloud, workflows and automation. But make no mistake, these technologies are closely tied and if your business is looking at building an automated, private cloud, you should also examine your software-defined networking strategy.
Which will the Commercial Space Adopt First?
Both!Many partners, customers and home tinkerers are already experimenting with technologies such as VMware’s VSAN. As the competitive market becomes more clear with these products headed towards their GA release, we will begin to see where they fit, capacity- and performance-wise, as well as architecturally and as part of organizations overall storage strategy. Will distributed technologies such as ScaleIO and VSAN become primary storage to back virtual machines? Or perhaps a secondary/tertiary tier for operating system virtual disks and data vaults? Another use case might be for disk-based virtual machine backups, which then tape-out if desired.
With the maturation of many automation and private cloud offerings, businesses starting down the path or increasing their adoption of SDDC will reap the benefit of years of experience growing and evolving these products. For many mid-market VMware customers, the software-defined networking features in vCloud Suite will fill a huge gap in their service feature-set. For those customers already deep into automation and provisioning at scale, NSX or ACI might more closely align to their needs.
For customers wondering how they can utilize software to scale their networking or storage services, this is a very exciting time in the industry to pose that question. For the new datacenter consumer, their question to traditional hardware vendors might not be “what features do you provide”, but “what constraints do you introduce?”
Kenny Garreau is a Cloud Architect for Lumenate, and is VMware Certified Design Expert #115.
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