問79
頻出度★☆☆
従来のサーバが個別に備える電源装置や外部インタフェースなどをサーバ間で共有し, 高密度化, 省スペース化を実現したサーバシステムはどれか。
平成21年度 春期 ITパスポート試験 問79
This question's explanation and your answers so far.
解説
問 79
Incorrectア
A tower server houses each server one by one in its own upright, standalone case resembling a desktop PC. Both the power supply unit and the external interfaces are provided individually by each case and are not shared. It stands on the floor and takes up a large footprint per unit, which is the opposite of high density and space savings.
Incorrectイ
A desktop server uses an ordinary PC case placed on a desk or on the floor directly as a server. It is aimed at small offices, and here too the power supply unit and the external interfaces are independent for each unit. Because it has no mechanism for consolidating many units, it does not fit the sharing between servers that the question describes.
- ウ
正解 The correct answer is ウ. A blade server is a server system in which board-shaped circuit boards (blades) that carry only the core server parts, such as the CPU, memory, and disk, are inserted, many at a time, into a dedicated case called an enclosure (chassis). The power supply units and external interfaces that the question says conventional servers each have individually are gathered on the chassis side in a blade system: power units, cooling fans, network switches, and the various interfaces are shared by all the blades. As a result, the parts and the volume needed per server are reduced, and more servers can be packed into the same rack space (high density, space savings). In addition, power cables and LAN cables can be bundled per chassis, so cabling is greatly reduced, and a server can be added or replaced simply by sliding a blade in or out, which is an operational advantage as well.
Incorrectエ
A rack-mount server places thin cases horizontally and stacks them level upon level in a 19-inch rack. Because the rack (the shelf) is a shared installation space, it saves more space than a tower server, but the power supply unit and the external interfaces are still provided individually by each case, and power cables and LAN cables must still be wired one unit at a time. It does not satisfy the sharing of power supply units and external interfaces that the question requires, so it falls short of the blade server and is wrong.
ここがポイント
- Blade server = a design in which many board-shaped servers (blades) are mounted in a dedicated case (an enclosure), and the power supply units, cooling fans, external interfaces, and network switches are shared on the chassis side. This sharing achieves high density, space savings, and less cabling.
- Remember server chassis form factors in order of consolidation: tower, then rack-mount, then blade. What a rack-mount server shares is only the rack as an installation space, while a blade server shares even the parts themselves, such as power supplies and interfaces; that difference is the key to telling the two apart.
用語