Log on - IT

Unix - what it means to you
Greg Wright, an IT consultant who provides training services to Tangent IT Services Ltd, explains
While many people are used to using Microsoft operating systems on desktop PCs, the majority of the world's mid-range computers run a version of Unix, an operating system that dates back to the 1960s.

An operating system is a program that is responsible for interfacing user programs with the computer hardware, and ensuring that all programs get a fair share of the resources available. It allows programmers to access the hardware in a well-defined and consistent way, and is also responsible for accessing the hardware in an efficient manner - for example, avoiding disk operations that are thousands of times slower than memory operations.

Properties of Unix
The properties of Unix are:
virtual memory - programs running on Unix run in their own protected memory space with memory resources allocated by Unix as and when they are needed
multi-user - all Unix flavours are multi-user operating systems, allowing many users to access the same host at the same time, typically over a network
multi-processor - all modern implementations of Unix provide sophisticated multi-processor support allowing programs and the operating system to run on several processors at the same time
64 bit - modern Unix versions support 64-bit processors and hence very large file sizes
PC and non-PC architectures - Unixes run on many different hardware platforms; many manufacturers support the PC architecture.

Modern Unix implementations
Modern Unix implementations also include:
PC integration - PCs' share and print services are provided by the Samba package; several commercial and non-commercial products allow Windows programs to run on Unix
the Open Source Movement - provides thousands of programs freely downloadable to run on Unix.

Its relative security is a key to the success of Unix. This ties in strongly with its hand-in-hand development with the Open Source Community. Most Unix code is freely available, meaning that it can readily be audited for security problems.

Unix is used by almost all major institutions for applications as far ranging as design services to bank databases. It runs on hardware from old 386 PCs to PC clusters with thousands of nodes to IBM Mainframes and other exotic architectures with very high bus throughput.

Unix knowledge opens up many career opportunities from system and database support through programming to technical design and architecture, and project management and implementation. A brief search for Unix on just one IT employment website shows strong demand for Unix skills (see Table 1).

Table 1

Query Results
Unix 2298
Unix and database 232
Unix and programming 258
Unix and manager 226
Unix and architect 81
Unix and security 202
Unix and support 775

A search on the most popular Unix flavours revealed the results shown in Table 2.

Table 2

Linux 333
Solaris (Sun) 735
HPUX (HP) 160
AIX (IBM) 197
FreeBSD 16
OSX (Apple) 9
Tru64 (Digital/Compaq/HP) 24

Demand for Unix skills is from many sources such as Internet service providers (ISPs), industrials, financials, defence and utilities. There is currently strong demand for people with Unix experience and DV security clearance.

Unix is highly accessible for hobbyists or self-study since the Linux version of Unix is freely available over the Internet. Source code for the kernel (the core of the Unix operating system), along with a number of companion books, is available for people who need an 'under-the-hood' knowledge.

Some areas of Unix administration, such as advanced disk management, back-ups and clustering, are somewhat idiosyncratic and are best learned in a formal training environment. Courses are available covering all aspects of administration and programming, from basic introductions to advanced clustering courses.

Many training establishments provide direct and online learning solutions. Taught courses tend to be modular and last from three to five days. They usually have a high percentage of time allocated to hands-on learning. People on a budget should start with a search of the Internet for useful information (many academic courses are published there). Another good starting point is LinuxFormat magazine. Many areas have a Linux users' group (see www.lug.org.uk) with members who cover all ranges of abilities and are often very happy to help beginners.

Unix is often used to support a business in an environment where hardware or software failures could be disastrous. Disciplined procedures are often used to control the introduction and testing of changes. People working in these environments need to be prepared to work out of hours and need to be able to operate well under pressure and as a part of a team.

Unix practitioners come from a vast range of academic backgrounds. Generally, aptitude and attitude are considered more important than raw academic achievement. Many IT managers started out as operators responsible for changing back-up tapes and reporting faults.

Tangent IT Services Ltd can be contacted on 01684 588466 or www.tangent-it.com

Its relative security is a key to the success of Unix
There is currently strong demand for people with Unix experience and DV security clearance

People working in these environments need to be able to operate well under pressure and as a part of a team