UNIX System Administration Handbook - Evi Nemeth [16]
See Chapter 10 for more information about backups.
Installing new software
When new software is acquired, it must be installed and tested, often under several versions of UNIX and on several types of hardware. Once the software is working correctly, users must be informed of its availability and location. Local software should be installed in a place that makes it easy to differentiate from the system software. This organization simplifies the task of upgrading the operating system since the local software won’t be overwritten by the upgrade procedure.
Monitoring the system
Large UNIX installations require vigilant supervision. Daily activities include making sure that email and web service are working correctly, watching log files for early signs of trouble, ensuring that local networks are all properly connected, and keeping an eye on the availability of system resources such as disk space.
Troubleshooting
UNIX systems and the hardware they run on occasionally break down. It is the administrator’s job to play mechanic by diagnosing problems and calling in experts if needed. Finding the problem is often harder than fixing it.
Maintaining local documentation
As the system is changed to suit an organization’s needs, it begins to differ from the plain-vanilla system described by the documentation. It is the system administrator’s duty to document aspects of the system that are specific to the local environment. This chore includes documenting any software that is installed but did not come with the operating system, documenting where cables are run and how they are constructed, keeping maintenance records for all hardware, recording the status of backups, and documenting local procedures and policies.
See page 809 for suggestions regarding documentation.
Auditing security
The system administrator must implement a security policy and periodically check to be sure that the security of the system has not been violated. On low-security systems, this chore might only involve only a few cursory checks for unauthorized access. On a high-security system, it can include an elaborate network of traps and auditing programs.
See Chapter 21 for more information about security.
Helping users
Although helping users with their various problems is rarely included in a system administrator’s job description, it claims a significant portion of most administrators’ workdays. System administrators are bombarded with problems ranging from “My program worked yesterday and now it doesn’t! What did you change?” to “I spilled coffee on my keyboard! Should I pour water on it to wash it out?”
1.7 HOW TO FIND FILES ON THE INTERNET
A wealth of information about system administration is available, in many forms. A list of “starter” resources can be found in Chapter 27, Policy and Politics.
The Internet is by far the richest deposit of information. You can type questions about system administration topics into any of the popular search engines, such as www.yahoo.com, www.altavista.com, www.google.com, and www.webopedia.com.
Many sites cater directly to the needs of system administrators. Here are a few that we especially like:
• freshmeat.com – a huge collection of Linux software
• www.ugu.com – the Unix Guru Universe; lots of stuff for sysadmins
• www.stokely.com – a good collection of links to sysadmin resources
• www.tucows.com – Windows and Mac software, filtered for quality
• slashdot.org – “the place” for geek news
• www.cpan.org – a central source for Perl scripts and libraries
• securityfocus.com – security info; huge searchable vulnerability database
1.8 SYSTEM ADMINISTRATION UNDER DURESS
System administrators wear many hats. In the real world, they are often people with other jobs who have been asked to look after a few computers on the side. If you are in this situation, you may want to think a bit about where it might eventually lead.
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