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1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesSoftware-defined technologies (SDx) use software to abstract and manage physical infrastructure. Instead of configuring every device or resource separately, administrators can apply policies and automation to logical pools of networking, storage, security, compute, and cloud resources. This guide explains the six SDx domains in Data Center Knowledge’s historical guide, published February 21, 2014, and puts its named products in that period’s context.
What does “software-defined” mean?
A software-defined system places a logical control and management layer between workloads or administrators and the physical resources that do the work. The software layer represents resources in a way that can be configured, grouped, allocated, or governed by policy; the underlying hardware still executes the networking, storage, or compute tasks.
The aim is more consistent management: make changes through software and policy rather than relying entirely on device-by-device configuration. “Software-defined” does not mean that hardware disappears, that every function is virtualized, or that a system automatically works across products from different vendors. The practical scope depends on what the software controls, which interfaces it supports, and how it handles the physical resources underneath.
How SDN, SDS, and the other SDx terms differ
SDx is an umbrella label, not one product or a single technical standard. Its variants describe which part of infrastructure is abstracted and managed in software.
#1 Best Overall
| Approach | What the software layer manages | Example cited in the 2014 guide |
|---|---|---|
| Software-defined networking (SDN) | Logical traffic control and network resources | VMware NSX and Cisco NX-OS |
| Software-defined storage (SDS) | Storage pools, request placement, and performance tiers | Atlantis ILIO USX and VMware Virtual SAN with Storage Policy Based Management |
| Software-defined security | Virtual security controls and policies associated with workloads | Check Point virtual appliances for AWS and Palo Alto Networks PAN-OS |
| Software-defined data center (SDDC) | Data-center-wide network, storage, compute, and management resources | VMware’s SDDC concept and IO Data Centers’ IO.OS |
| Software-defined infrastructure (SDI) | Infrastructure profiles and hardware resources that can be re-provisioned | Cisco UCS |
| Software-defined cloud | Resources orchestrated across private, public, or hybrid cloud environments | Citrix CloudPlatform and OpenStack |
These product names are historical examples from the 2014 guide, not confirmation that a product remains available, unchanged, or a current market leader. Verify current product names, support, capabilities, and licensing with the vendor before making a technology decision.
What each software-defined approach does
Software-defined networking (SDN)
SDN abstracts network control so traffic can be managed logically rather than depending solely on configuring each physical device independently. In the 2014 guide, VMware NSX illustrated programming and provisioning virtual and physical resources; Cisco NX-OS illustrated a modular network operating system. These examples represent different kinds of software in network management, not proof that the products are interchangeable or implement the same architecture.
Software-defined storage (SDS)
SDS adds a software layer that can direct storage requests to appropriate pools or tiers. The guide describes pooling resources that include direct-attached storage (DAS), flash, solid-state drives, spinning disks, and RAM. Its examples were Atlantis ILIO USX and VMware Virtual SAN paired with Storage Policy Based Management, illustrating aggregation and policy-driven placement. Pooling can give administrators a way to match workloads with storage resources, but the result depends on the system’s supported media, policies, and operational design.
Software-defined security
Software-defined security applies controls through virtualized or centrally managed software. The 2014 guide discusses intrusion prevention systems (IPS), access controls, data loss prevention (DLP), unified management, and dynamic address groups. It also describes synchronizing policies with the creation of virtual workloads. The intended operational benefit is to apply security controls in step with changing workloads; the named Check Point and Palo Alto Networks products are examples from that historical article, not a statement about their present features or availability.
Software-defined data center (SDDC)
An SDDC extends software-based control across data-center domains: networking, storage, compute, and management. The guide presents VMware’s SDDC concept as a way to unify those resources in a virtual layer for greater control and resiliency. It also cites IO Data Centers’ IO.OS as a logical management layer for a distributed data-center platform. SDDC describes a broad scope; the label alone does not establish how much of a particular environment is automated or how resilient it is.
Software-defined infrastructure (SDI)
SDI applies configurable software profiles to infrastructure resources so they can be re-provisioned for different needs. The guide uses Cisco UCS to illustrate profiles that could be adjusted according to workload, user location, or time of day across racks and data centers. The example is about changing resource configuration through profiles, not removing the need to manage hardware capacity and compatibility.
Software-defined cloud
Software-defined cloud describes orchestration across infrastructure domains and cloud environments, including private, public, or hybrid deployments. The guide names Citrix CloudPlatform and OpenStack as examples for coordinating workloads across those settings. Its central idea is abstraction across network, storage, compute, and data-center resources; the exact degree of portability depends on the interfaces and services available in each environment.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How to assess an SDx approach
A software-defined label is less informative than the system’s actual control boundary and operating model. Before adopting an approach, assess it against the environment it must manage:
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Best Value
- Control-plane abstraction: Identify what the software controls and what still requires direct hardware configuration.
- Scope: Establish whether it covers networking, storage, security, compute, cloud resources, or only a subset.
- Automation and policy: Check which changes can be automated, how policies are applied, and how exceptions are handled.
- Interoperability: Verify supported standards, APIs, devices, and integrations rather than assuming that “software-defined” means vendor-neutral.
- Operational visibility: Determine whether administrators can observe resource allocation, policy effects, and failures across the managed layer.
- Resiliency: Understand how the design handles software-layer outages, hardware failures, and recovery.
- Migration and skills: Account for migration complexity, the expertise needed to operate the system, and changes to existing procedures.
- Licensing and lock-in: Review the licensing model and the practical effort required to move policies, workloads, or data to another platform.
What the 2014 guide establishes—and what it does not
Bill Kleyman’s Data Center Knowledge guide, published February 21, 2014, is a period explainer of the SDx vocabulary and examples then used in the data-center industry. It describes a common architectural idea: use software abstraction and policy to manage physical resources more consistently. Its named products should be read as examples from that date, not as a current shortlist.
The guide does not publish market-size, adoption, return-on-investment, or performance statistics. It therefore cannot support a numerical claim about how much SDx improves cost, speed, or resilience. Those outcomes depend on the system selected and the environment in which it is deployed.
Quick Recap
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