对于一般的从业人员来讲，他们的第一反应会是在一个宿主机上运行一个或多个虚拟(客户)操作系统。
The first concept that comes to the mind of the average industry professional is running one or more guest operating systems on a host.
我曾经看到一个操作系统被一个两年来每天都在运行的两行清理脚本擦除。
I once saw an operating system wiped out by a two-line cleanup script that had been working every day for two years.
在本文的背景下，在硬件上直接运行的操作系统是一个物理系统(或者“非虚拟化系统”)。
In the context of this article, an operating system running directly on hardware is a physical (or non-virtualized) system.
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