Why would cloud providers (or enterprises for that matter) build and operate their data centers this way? This approach to data center architecture and operations provides three key benefits over more traditional legacy data centers.
Agility – The fact that everything is “software-defined”, including servers, storage, and networking, makes cloud data centers far more agile and adaptable to changing business requirements. Instead of having to install and configure hardware like servers and disk subsystems (which requires smart, expensive people), software-defined resources can be provisioned and configured through software, in particular IT orchestration software.
Reduced operating costs – The extensive virtualization and automation made possible by software-defined everything makes data center operations more reliable and less expensive. Common, repeated tasks like provisioning, patching, and reconfiguration of servers, networking, and storage can be managed by the orchestration software, essentially the automated version of the classic data center runbook.
Better application scalability and availability – Because the hardware and server environments are standardized, and because they can all be provisioned and configured with software, properly architected applications can scale better and be far more available, meaning they will suffer from less scheduled and unscheduled downtime. Software-defined networking provides load balancing services in front of redundant application servers, allowing new patched servers to be provisioned, and unpatched or failed servers to be deprovisioned, all without affecting application availability.