To write low-level scripts, as an admin, you need to know whether you are currently on a physical or a virtual machine. Charly finds out with a couple of clever hacks.
Of the systems I work on, about 90 percent are virtualized and 10 percent are legacy hardware servers. For many jobs, this makes no difference, but when I write scripts that call or change hardware-related functions, I need this information.
If I have root privileges on the system and am also allowed to retroactively install software, the problem can be solved very quickly. I install either Facter  or
virt-what . Facter provides extensive information about the system’s hardware, much like
lshw, and is actually overkill for answering the “virtual or not” question. Calling
facter virtual returns the virtualization platform as the answer, such as
kvm. The same result is returned by a call to
virt-what. If I don’t need the power of Facter elsewhere, I prefer the leaner
If I have root privileges but am not allowed to install software (for example, because of restricted repositories), there is another possibility. The command
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