Blade server

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Template:Cleanup-date A blade server is essentially a housing for a number of individual minimally-packaged computer motherboard "blades", each including one or more processors, computer memory, computer storage, and computer network connections, but sharing the common power supply and air-cooling resources of the chassis. The idea is that by placing many blades in a single chassis, and then 19-inch rack-mounting them, systems can be more compact and powerful, but less expensive than traditional systems based on mainframes, or server farms of individual computers.

Uses

Blade servers are ideal for specific purposes such as web hosting and cluster computing. Individual blades are typically hot-swappable. One of the greatest advantages of blade servers is that they allow the use of a single reliable heavy-duty DC power supply, rather than many small and potentially unreliable power supplies. However, that power supply is a single point of failure. For that reason, manufacturers add redundancy by installing two power supplies per enclosure, so if one fails, the system will continue to operate. Additionally, because blade servers use custom-designed blade boards rather than commodity PC motherboards, they can be designed to have significantly more efficient air-cooling airflow than a rack of servers.

Blade servers increasingly allow the inclusion of functions such as network switches and routers as individual blades.

Although blade server technology in theory allows for open, cross-vendor solutions, at this stage of development of the technology, users find there are fewer problems when using blades, racks and blade management tools from the same vendor. Eventual standardization of the technology might result in more choices for consumers; increasing numbers of third-party software vendors are now entering this growing field.

Blade servers are not, however, the answer to every computing problem. They may best be viewed as a form of productized server farm that borrows from mainframe packaging, cooling, and power supply technology. For large problems, server farms of blade servers are still necessary, and because of blade servers' high power density, can suffer even more acutely from the HVAC problems that affect large conventional server farms.

History

Complete microcomputers were placed on cards and packaged in standard 19-inch racks in the 1970s soon after the introduction of 8-bit microprocessors. This architecture was used in the industrial process control industry as an alternative to minicomputer control systems. Programs were stored in EPROM on early models and were limited to a single function with a small realtime executive.

The name blade server appeared when cards included small hard disks or flash memory program storage. This allowed complete server operating systems to be packaged on the blade.

The architecture of blade servers is expected to move closer to mainframe architectures. Although current systems act as a cluster of independent computers, future systems may add resource virtualization and higher levels of integration with the operating system to increase reliability.de:Bladeserver ja:ブレードサーバ th:เบลดเซิร์ฟเวอร์