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Virtualized servers do all the good and bad things regular servers do. They boot up, power down, suspend, hang, and even crash. If a guest OS or a device driver it uses is buggy, the virtual PC will crater. But not the physical computer, and that’s key.
If your OS crashes or an application hangs, or even if you install a software fix that requires a reboot, nothing happens to the hardware. One virtual machine can fail over to another in a purely virtual sense or in a way that’s closer to the real thing. Even if certain hardware devices have malfunctioned, so long as the fail-over target is configured to use a secondary network adapter and an alternate path to storage, the fail-over will work exactly as it would if the virtual PCs were physical PCs.
In most cases, an enterprise management system will monitor and react to a virtual fail-over as if it were the real thing. Solutions such as HP OpenView see and interact with virtual servers the same way they do with physical ones. The reported configurations of the servers will change after they’re virtualized, but it’s entirely likely that the day-to-day management of your shop will experience little change.
In addition, most virtualization systems bundle solution-specific management software, allowing an administrator to sit at a central console and manipulate all the virtual servers in an enterprise. It’s quite an eye-opener to swap out a virtual Ethernet card without ever touching the hardware.
A virtualization solution’s management console gives you a degree of control over your virtual PCs that surpasses what administrators can do with traditional tools. From a central location, you can boot and shut down virtual PCs as needed. It’s also possible to pause them, which harmlessly freezes them in their current state, or hibernate them, putting them in a deep freeze by saving their state to a file on disk. By overwriting the disk file, you can restore PCs from a backed-up state and roll back changes that rendered the guest inoperable, all from a terminal session.