Question

计算机文章翻译

In environments with a mix of operating systems——a common condition that turns even simple consolidation into a messy affair—— one solution would be to host each OS in its own VM. For example, on a PC server running one of VMware’s virtualization solutions, you can run any combination of Windows 2003 Server, Windows 2000, Windows NT 4.0, various flavors of Linux, and FreeBSD. You can even use VMs to host different versions of the same OS. Linux software is infamous for dependence on specific versions and vendor distributions of Linux. Virtualization is the only way to run applications designed for Red Hat 7.2 and Suse 9.0 simultaneously on a single server.

Virtualization is magnificent stuff, but it doesn’t cure all ills. You can never create a virtual PC that outperforms the physical system underneath. You will learn much about your applications’ system requirements from moving them to a virtual environment. They’ll likely surprise you, either with how little of the original server they used——that’s the typical case——or how piggish they are. If necessary, you can throttle the nasty ones down.

And while one of the great benefits of virtualization is security——it’s hard to accomplish much by cracking a system that doesn’t exist——a virtualized PC can still be compromised. Fortunately, the cure is to overwrite the virtual PC’s disk image with one that’s known to be clean, but managing virtual servers still requires vigilance.

Ultimately, hardware consolidation is only one reason to opt for server virtualization, and it has wide appeal. Still, depending on each department’s unique needs, IT managers are sure to find innumerable ways that virtualization can benefit your enterprise.

Answer 1

在多种操作系统混用的环境下（这是一种常见的情况，会把简单的服务器集中弄得乱七八糟），一种解决办法就是将每个OS在各自虚拟机上运行。例如，在一台运行VMware虚拟方案的PC服务器上，你能运行Windows 2003 Server、 Windows 2000、 Windows NT 4.0、各种版本的Linux以及FreeBSD的各种组合。甚至能运行同一OS的不同版本。Linux因对特定版本和厂商有依赖性而搞得名声狼藉。虚拟化是惟一的方法，让一台服务器上同时运行为Red Hat 7.2 和Suse 9.0设计的应用程序。

虚拟化是个好东西，但它不能包治百病。你永远不能建立一个虚拟PC机，其性能超过它所在的物理系统。将应用程序移到虚拟环境，你能从中学到很多应用程序的系统要求。它们可能让你吃惊，不是它们只用了原来服务器非常少的一部分（这是一种很典型的情况），就是它们是多么的贪婪。如果有必要，你就能关闭那些讨厌的程序。

虚拟化最大的好处之一是安全（破坏实际不存在的系统是难以实现的），同时虚拟化的PC机还能做出妥协。办法是把虚拟PC机的磁盘映像重写到已知是干净的磁盘上，但是管理虚拟服务器仍需要警惕。

归根结底，硬件集中不是选择服务器虚拟化的惟一理由，它还有很广泛的需求。依据每个部门不同的要求，IT管理人员一定能找到数不清的方法，让虚拟化为企业服务。