System administrators are the professionals that provide specific services in the system software arena. These professionals are often known by their acronym SYSADMIN. A system administrator
performs various tasks while taking care of multiple, often heterogeneous, computer systems in an attempt to keep them operational. When computer systems are connected to the network, which is
almost always the case today, the system administration also includes network−related duties.
UNIX administrators are part of the larger family of the system administrators. Their working platform is UNIX, and it caries many specific elements that make this job unique. UNIX is a powerful
and open operating system. As with any other software system, it requires a certain level of customization we prefer the term configuration and maintenance at each site where it is
implemented. To configure and maintain an operating system is a serious business; in the case of UNIX it can be a tough and sometimes frustrating job. Why is UNIX so demanding? Here are some
observations:
A powerful system means there are many possibilities for setting the system configuration. •
An open system results in permanent upgrades with direct impacts on administrative issues. •
UNIX is implemented at the most mission critical points, where a downtime is not allowed. •
Networking presents a new challenge, but also a new area of potential problems. •
Different UNIX flavors bring additional system administration difficulties. •
Networking in particular, with its many potential external failures, can affect a UNIX system significantly. Periodical global network degradation too high of a load, low throughput, or even
breaks in communication can cause complex problems and bring a lot of headaches. It is easy to be misguided in tracing a problem, and to be looking for the source of troubles at the wrong place.
Usually at such times everyone is looking to the UNIX people for a quick solution. The only advice is: Be ready for such situations.
As a matter of fact, system and network administration are relatively distinct duties, and sometimes they are even treated separately. However, it is very common to look at system and network
administration as two halves of the same job, with the same individuals or team responsible for both. It is fair to say that the term network administration is strictly related to the computer system
as part of the network, and remains within the network service boundaries required for the computer functioning in the network environment. It does not cover core network elements like switches,
bridges, hubs, routers, and other network−only devices. Nevertheless, the basic understanding of these topics also could make overall administration easier.
So to get to the heart of the topic, let us start with a brief discussion of the administrators role, duties, guidelines, policies, and other topics that make up the SYSADMIN business. Most of the
paragraphs that follow are not strictly UNIX related, although our focus remains on UNIX systems and network administration.
1.4.1 System Administrators Job
Understanding system administrators background, training, and the kind of job performance to be expected is challenging; too often, employers fall back into misusing the job classifications with
which they are familiar. These job classification problems are exacerbated by the scarcity of job descriptions for systems administrators. One frequently used misclassification is that of programmer
or software engineer. Production of code is the primary responsibility of programmers, not of the systems administrator. Thus, systems administrators classified as programmers often receive poor
evaluations for not being productive enough. Another common misclassification is the confusion of
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The following text lists the main elements that describe the system administrators job at various levels. The basic intention is to describe the core attributes of systems administrators at various
levels of job performance, and to address site−specific needs or special areas of expertise that a systems administrator may have.
Generally, as for many other professions, system administrators are classified regarding their background and experience into several categories:
Novices
Required background: 2 years of college or equivalent post−high−school education or experience
♦ Desirable background: a degree or certificate in computer science or a related field.
Previous experience in customer support, computer operations, system administration, or another related area; motivated to advance in the profession
♦ Duties: performs routine tasks under the direct supervision of a more experienced
system administrator; acts as a front−line interface to users, accepting trouble reports and dispatching them to appropriate system administrators
♦ •
Junior
Required background: 1 to 3 years system administration experience ♦
Desirable background: a degree in computer science or a related field, familiarity with networkeddistributed computing environment concepts for example, can use the
route command, add a workstation to a network, and mount remote filesystems; ability to write scripts in some administrative language Tk, Perl, a shell;
programming experience in any applicable language ♦
Duties: administers a small site alone or assists in the administration of a larger system; works under the general supervision of a system administrator or computer
systems manager ♦
•
IntermediateAdvanced
Required background: three to five years systems administration experience ♦
Desirable background: a degree in computer science or a related field; significant programming background in any applicable language
♦ Duties: receives general instructions for new responsibilities from supervisor;
administers a midsized site alone or assists in the administration of a larger site; initiates some new responsibilities and helps to plan for the future of the sitenetwork;
manages novice system administrators or operators; evaluates andor recommends purchases; has strong influence on purchasing process
♦ •
Senior
Required background: more than five years previous systems administration experience
♦ Desirable background: a degree in computer science or a related field; extensive
programming background in any applicable language; publications within the field of system administration
♦ •
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This is a general job classification and description for potential UNIX administrators. It can easily vary from one site to another, especially regarding official job titles. A number of other skills could
also be considered:
Interpersonal and communication skills; ability to write proposals or papers, act as a vendor liaison, make presentations to customer or client audiences or professional peers, and work
closely with upper management •
Ability to solve problems quickly and completely; ability to identify tasks that require automation and automate them
• A solid understanding of a UNIX−based operating system, including paging and swapping,
inter−process communication, devices and what device drivers do, filesystem concepts inode, superblock, and use of performance analysis to tune systems
• Experience with more than one UNIX−based operating system; with sites running more than
one UNIX−based operating system; with both System V and BSD−based UNIX operating systems; with non−UNIX operating systems for example, MS−DOS, Macintosh OS, or
VMS; and with internetworking UNIX and other operating systems MS−DOS, Macintosh OS, VMS
•
Programming experience in an administrative language shell, Perl, Tk; extensive programming experience in any applicable language
• Networking skills — a solid understanding of networkingdistributed computing environment
concepts, principles of routing, clientserver programming, and the design of consistent networkwide filesystem layouts; experience in configuring network filesystems for example,
NFS, RFS, or AFS, in network file synchronization schemes for example, rdist and track, and in configuring automounters, license managers, and NIS; experience with TCPIP
networking protocols ability to debug and program at the network level, with non−TCPIP networking protocols for example, OSI, Chaosnet, DECnet, Appletalk, Novell Netware,
Banyan Vines, with high−speed networking for example, FDDI, ATM, or SONET, with complex TCPIP networks networks that contain routers, and with highly complex TCPIP
networks networks that contain multiple routers and multiple media; experience configuring and maintaining routers and maintaining a sitewide modem poolterminal servers;
experience with X terminals and with dial−up networking for example, SLIP, PPP, or U U C P ; e x p e r i e n c e a t a s i t e t h a t i s c o n n e c t e d t o t h e I n t e r n e t , e x p e r i e n c e
installingconfiguring DNSBIND; experience installingadministering Usenet news, and experience as postmaster of a site with external connections
•
Experience with network security for example, building firewalls, deploying authentication systems, or applying cryptography to network applications; with classified computing; with
multilevel classified environments; and with host security for example, passwords, uidsgids, file permissions, filesystem integrity, use of security packages
•
Experience at sites with over 1000 computers, over 1000 users, or over a terabyte of disk space; experience with supercomputers; experience coordinating multiple independent
computer facilities for example, working for the central group at a large company or university; experience with a site with 100 uptime requirement; experience
developingimplementing a site disaster recovery plan; and experience with a site requiring charge−back accounting
•
Background in technical publications, documentation, or desktop publishing •
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Experience with hardware: installing and maintaining the network cabling in use at the site, installing boards and memory into systems; setting up and installing SCSI devices;
installingconfiguring peripherals for example, disks, modems, printers, or data acquisition devices; and making board−level and component−level diagnosis and repairing computer
systems •
Budget responsibility, experience with writing personnel reviews and ranking processes; and experience in interviewinghiring
• Do not be afraid of this long list of additional requirements. Nobody expects UNIX systems and
network administrators to be Supermen. UNIX administration is a normal job that is demanding but definitely doable.
To end this discussion, here is a joke about UNIX administrators. Consider the similarities between Santa Claus and UNIX administrators:
Santa is bearded, corpulent, and dresses funny. •
When you ask Santa for something, the odds of receiving what you wanted are infinitesimal. •
Santa seldom answers your mail. •
When you ask Santa where he gets all the stuff he has, he says, Elves make it for me. •
Santa does not care about your deadlines. •
Your parents ascribed supernatural powers to Santa, but did all the work themselves. •
Nobody knows who Santa has to answer to for his actions. •
Santa laughs entirely too much. •
Santa thinks nothing of breaking into your HOME. •
Only a lunatic says bad things about Santa in his presence. •
1.4.2 Computing Policies
