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 Generate Revenue Through IT Using Business Service Management
Sponsored by HP
Making sure that your business applications are available to their end users is an important part of running your business smoothly. Business operations have evolved to where IT must now broaden its focus to help the company attract, retain and grow customer relationships and increase customer satisfaction. Business service management (BSM) helps lay the foundation by managing services in dynamic support of business requirements. »
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Managing the Modern Network
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Networks are more than vehicles to transport e-mail and Web pages. In a global economy where information crosses the globe in an instant, and where Web-based applications power business, it's more important than ever to ensure your network is safe from threats and optimized to deliver the data your business needs. »
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Storage Networking 2, Configuration and Planning
Sponsored by HP
In Part 1, we discussed storage area networks (SANs) and fibre channel. In Part 2, delve into best practices and cover the general concepts you must know before configuring SAN-attached storage. The most critical, sometimes tedious, part of setting up a SAN is configuring each individual disk array. This guide examines configurations for SAN-attached servers and disk arrays, and also includes a look at the future of IP storage.
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Is Your Disaster Recovery Plan Good Enough? Get Disaster Recovery Right
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Preparing for a disaster is more often than not part of the storage planning process, and without question it is one of the most difficult task, since it includes local hardware and software, networking equipment, and a test plan to ensure that you can recover from the disaster. Learn how to put your organization on the proper disaster recovery plan, now. »
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What is UNIX
July 19, 1998
What is an Operating
System
When you really get down to the nitty
gritty, a computer is simply a hunk of machine with a bunch
of on/off switches. The patterns created by these on/off
switches, represented by ones and zeros, are assigned
meaning by the people who build the machines (by the
"machine" I mean hardware, such as a CPU, a monitor, or a
sound card).
| "An
operating system
is a living, breathing software entity.
The soul of the computing machine, it is the nervous system
that turns electrons and silicon into a personality. It
brings life to the computer." - from Mike Gancarz's "The UNIX
Philosophy" |
For example, an engineer designing a
sound card for a computer might specify that if all the
switches are turned on, the card will generate a
loud and annoying beep.
Turning a switch to on or off
typically involves sending the switch an electrical signal of a
certain voltage.
As you can imagine, telling the
hardware to do things is a bit of a cryptic process.
Generating beeps might seem simple enough, but when you
imagine the complexity of defining and manipulating memory,
creating file systems, executing applications, and plenty of
other tasks demanded of computers today, you can see how
manipulating on/off switches could get overwhelming pretty
quickly.
In fact, if you had to speak to the
hardware itself, you would probably spend all your time
coding machine instructions instead of actually doing your
work.
Fortunately, instead of forcing users
to talk to the hardware directly, most computers have some form of
"operating system" (also known as OS) which provides a "layer of
abstraction"
around the hardware.
The OS sits between users and hardware
providing translation services. The great benefit of the
OS is that you need not know how to speak
the language of the hardware or how to perform basic tasks
such as the definition of memory or the allocation of
disk space using the hardware. The OS knows
how to do all of that itself. And what's more, it can speak to
the hardware much faster than you could.
All you need to know how to do is talk
to the OS. And fortunately, talking to the OS
is much easier than talking to the hardware since the
OS is typically designed to speak a language
more similar to human languages.
In UNIX, the operating system is broken
into three pieces:
the kernel,
the shell,
and the built-in
utilities.
The kernel is responsible for low level hardware communication,
the shell provides human users with a user-friendly interface,
and the built-in utilities provide basic tools for doing work.
Let's take a look at the kernel first
Additional Resources:
What is UNIX
Introduction to UNIX for Web Developers | Table of Contents
The UNIX Kernel
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Generate Revenue Through IT Using Business Service Management
Managing the Modern Network
Storage Networking 2, Configuration and Planning
Is Your Disaster Recovery Plan Good Enough? Get Disaster Recovery Right