everything that happens before you start typing commands on the
keyboard. It's the alarm system that calls the
police department when a late-night thief tries to break into your
building. It's the key lock on your
computer's power supply that makes it harder for
unauthorized people to turn off the machine. It's
the locked computer room with the closed-circuit camera that prevents
unauthorized physical access to your servers and communications
infrastructure. And it's the uninteruptable power
supply and power conditioners that help isolate your computers from
the vagaries of the power grid.
This chapter discusses basic approaches to physical security. It is
for people who think that this type of security is of little or no
concern?unfortunately, the majority of system administrators.
Despite the fact that physical security is often overlooked, it is
extraordinarily important. You may have the best encryption and
security tools in place, and your systems may be safely hidden behind
a firewall. However, if a janitor working late at night for your
cleaning service decides to steal a laptop or server
that's been left out on a table in
somebody's cubicle, those other fancy defenses
aren't going to be much help.
It should go without saying that in an emergency or disaster
situation, the lives and safety of personnel should always come
before data or equipment. Although there may be very limited
exceptions to this rule (in certain military situations), you should
never lose sight of what is truly irreplaceable.