[dgplug-users] Excellent explanation of super user concept by Clifford Stoll

[Nishant Pani]

I was reading this book "Cuckoo's Egg" by Clifford Stoll.In this he gives
an excellent explanation of the super user concept which is as follows



To satisfy a hundred users at once, the computer's operating system splits
the
hardware resources much as an apartment house splits a building into many
apartments. Each apartment works independently of the others. While one
resident
may be watching TV, another talks on the phone, and a third washes dishes.
Utilities—electricity, phone service, and water—are supplied by the
apartment
complex. Every resident complains about slow service and the exorbitant
rents.
Within the computer, one user might be solving a math problem, another
sending
electronic mail to Toronto, yet a third writing a letter. The computer
utilities
are supplied by the systems software and operating system; each user
grumbles about
the unreliable software, obscure documentation, and the exorbitant costs.
Privacy within the apartment house is regulated by locks and keys. One
resident
can't enter another's apartment without a key, and (if the walls are
sturdy), one
resident's activity won't bother another. Within the computer, it's the
operating
system that ensures user privacy. You can't get into someone's area without
the
right password, and (if the operating system is fair about handing out
resources),
one user's programs won't interfere with another's.

But apartment walls are never sturdy enough, and my neighbor's parties
thunder
into my bedroom. And my computer still slows down when there's more than one
hundred people using it at one time. So our apartment houses need
superintendents,
and our computers need system managers, or super-users.
With a passkey, the apartment house superintendent can enter any room. From
a
privileged account, the system manager can read or modify any program or
data on
thecomputer. Privileged users bypass the operating system protections and
have the
full run of the computer. They need this power to maintain the systems
software
("Fix the editor!"), to tune the operating system's performance ("Things
are too
slow today!"), and to let people use the computer ("Hey, give Barbara an
account.").

Privileged users learn to tread lightly. They can't do much damage if
they're
only privileged to read files. But the super-user's license lets you change
any
part of the system— there's no protections against the super-user's mistake
s.