May 2024
Intermediate
248 pages
6h 59m
Japanese
Content preview from 図解まるわかり 仮想化のしくみ
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仮想化の歴史は1960 年代まで遡ります。 当時コンピュータシステムは
汎用機（メインフレーム）で動作していました。汎用機に接続しているイ
ンテリジェント端末と呼ばれる端末に汎用機から入力フォームを送り、端
末側で入力後にEnterキーで情報を汎用機に送信して処理していました。
もしくは、より安価なダム端末を使って入力項目単位で汎用機と通信して
処理する使い方をすることもありました。
当時の汎用機は一度に1 つのプログラムしか実行できなかったため、入
力データを用意しても自分の順番が回ってくるまで待つ必要がありました
（図 1-5）。これを解決するために、CPUの実行時間を極めて短い時間に分
割して順次割り当てることで、仮想的にCPUがいくつも存在しているか
のように振る舞い、入力待ち時間を削減する方法が考えられました。
ジョン・マッカーシー博士は1961年のマサチューセッツ工科大学にお
ける100 周年記念式典のスピーチでタイムシェアリングのしくみを想定
し、「（ 水道や電力のように）コンピュータの能力や特定のアプリケーショ
ンを販売するビジネスモデルを生み出すかもしれない」と述べています。
この技術は後にタイムシェアリングシステム（TSS）という技術で利用
されるようになります（図1-6）。
当時の汎用機は非常に高価で、1966 年に出荷が始まったSystem/360
Model 75 は 350 万ドル、当時の為替レート（固定）で約 8 億円でした。
1960 年後半にはTSSを使って電話回線でコンピューティングサービス ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.