Due to the increasing importance of virtualization and cloud computing in the enterprise, the Software Defined Data Center, or Virtual Data Center, is gaining momentum. Once applications are separated from underlying hardware, it makes sense to push the concept further. And once application assets reside in a nebulous cloud that may be difficult for IT to gain visibility into, let alone maintain and manage, ideas like Software Defined Data Centers (SDDC) start to make a quite a bit of sense.
To date, the only Software-Defined market with any real traction is for Software Defined Networking products. A 2012 study by IDC predicted that SDN spending would reach $360 million in 2013, expanding to $3.7 billion by 2016.
Analyst forecasts aren’t the only way to measure the potential of SDN, though. In 2012, VMware acquired SDN startup Nicira for $1.26 billion. Brocade, Cisco, and Juniper followed suit by acquiring Vyatta, Cariden, and Contrail, respectively. Moreover, VCs are pouring serious money into this sector, heavily financing such startups as Affirmed Networks ($103 million raised to date), Big Switch Networks ($45 million), and Plexxi ($48 million).
From SDN to SDDCs
Building on SDN’s success, the SD concept has migrated to storage, security, and, now, the entire data center. At the most basic level, what SDN does is separate the control plane (or the built-in management logic firmware) from the data plane (which forwards network traffic to other devices) of networking devices.
Unlike virtualization, where the early focus was on server consolidation, SDN separation makes it possible to program the entire network in a different way. This shift makes it possible for applications themselves to control networking and security features. Or control functions could eventually be centralized and unified into some sort of higher-level cloud control plane or management suite.
In contrast, the status quo is that a device from Cisco or Juniper or whomever ships with vendor-supplied firmware that handles control and invariably results in all sorts of vendor-lock issues. Thus, another benefit of SDN is the ability to exercise unified control in a heterogeneous environment.
Software Defined Storage builds on this concept, treating various storage devices as a single pool of storage, which can be controlled centrally. The Software Defined Data Center, then, is an additional layer of abstraction above the other virtualization and SDx layers, which provide centralized control of all of these assets, not matter where they are located.
“While originally I was skeptical about any SDx assignation, the more I think about SDDCs the more the concept resonates,” David J. Cappuccio, Research VP at Gartner, noted. “The idea is that in a perfect world data center resources would be placed where it made the most economic sense, and then the allocation and use of those resources could be controlled by rules and analytics, allowing both workflows and workloads to be moved, or directed, where they best served the business at any particular point in time.”
Why are SDDCs important?
A number of factors are converging to accelerate the interest in SDx products. For starters, networks are getting bigger, faster, and far more complicated. Meanwhile, applications are breaking away from their siloes and being shifted to the cloud, mobile devices, connected home appliances, the M2M world, etc.
The rapid adoption of cloud computing means that traditional hardware-based networking just won’t keep up with the needs of both service providers and cloud consumers.
The same is true for storage. In theory, cloud computing makes automatic backups and disaster recovery practically table-stakes features for cloud services, but VM sprawl and network constraints hinder that vision.
Let’s also not forget the spread of WLANs in the enterprise. The various networking devices associated with WLANs (and serving Bring Your Own Device employees) are also sprawling practically out of control. As such, wouldn’t it make sense to centralize the control of the many WLAN switches and APs scattered through corporate campuses?
Finally, all of these new application consumption models introduce numerous new security risks. SDx could help security to evolve beyond its perimeter-protection roots into something that better matches today’s cloud and mobile environments. Moreover, IT security pros would be able to shift from a reactionary, firefighting mode, so they could actually spend time analyzing data and behaviors in order to proactively secure dynamic environments.
Add all of this up and the SDDC concept reaches beyond the data center to deliver services from the right place to the right end user in an efficient manner.
The Seven Properties of Network Virtualization
Before being acquired by VMware, the founders of Nicira laid the groundwork for SDDCs by defining “The Seven Properties of Network Virtualization”:
1. Interdependence from network hardware
2. Faithful reproduction of the physical network service model
3. Follow operational model of compute virtualization
4. Compatible with any hypervisor platform
5. Secure isolation between virtual networks, the physical network and the control plane
6. Cloud performance and scale
7. Programmatic network provisioning and control
Boiling down what all of this actually means, the properties essentially say:
1) Avoid outdated vendor-lock architectures
2) Be sure to factor in all of those legacy workloads that weren’t written for virtualized and cloud environments, but which won’t be phased out any time soon
3) Support the networking of VMs in the same way they were designed, i.e., don’t limit VM flexibility