The Complete Handbook of Blade Server Enclosures

Chapter 1: Understanding Blade Server Enclosures

A blade server enclosure is a chassis that does more than hold a stack of computers. It is the power distribution unit, the network switch, the KVM switch, the thermal management system, and the physical security boundary all built into a single 7U to 14U frame. Instead of racking twelve independent 1U servers, each with its own power supplies, network ports, and management interfaces, you install one chassis into the rack and slide twelve thin, modular server boards into its bays. Those server boards are the blades. They have no external cabling, no front panel to speak of, and no individual power supplies. They are designed to be installed and removed from the front of the unit in a matter of seconds.

This transformation of form factor requires a fundamental change in how you think about server hardware. A stand-alone server is a closed system. It has its own power conversion, cooling fans, network interfaces, and management controller. Each one of those parts adds cost, consumes power, and generates heat. A blade server, on the other hand, is an open module. It relies on shared resources located in the chassis. Those resources include power supplies, cooling fans, network interconnect switches, and a management module. The central element that ties it all together is the midplane, a large printed circuit board that sits vertically in the center of the chassis and provides sockets for the blades on the front and for the shared resources on