Introduction to task automation

An important part of administration is the ongoing maintenance of the machine. Because a Unix environment changes it needs to be checked on periodic basis.
Maintenance issues include:

Daily
- remove unused or unneeded core files,
- get rid of files no longer in use in the /tmp directory,
- monitor the disk space on user home directories
Weekly
- performing checks on the filesystem
- check for long running processes
- clear files that receive log information.
Monthly
- run monthly reports
- locate large files that are not being used

System administrators could easily spend every minute of every day performing periodic maintenance tasks unless they find a method of automation. Automation entails creating scripts that the system can execute at a particular time each week, day, or month. Automation also includes the simplification of interactive tasks by creating scripts or programs. Tasks that are repeated often and are complicated or tedious are good candidates for both simplification and automation.

Most Unix systems have a standard message logging process, which is performed by the syslog daemon. Because, nearly all Unix system administrators find it necessary to provide maintenance on this logged data, it is essential that the message logging facilities are understood. Users, however, are the most dynamic element of a system because they cause of most of the changes that occur. The Unix environment must be tailored to the way the users use the system.

One example might be: a Unix machine that supports a development environment (C programming or otherwise). Users writing and testing programs have a strange way of making mistakes and subsequently create, usually large, files or runaway processes that "upset" the machine. A system administrator must be able to correct the "upset" before the system crashes or becomes unusable. It advisable for the system administrator to be aware of problems that come about before users start screaming.

What can be automated? What should be automated? These are ongoing questions for every system administrator. Some say, automate everything. If the task can be accomplished with a script or program then it's easy to add it to the list of automated or periodic processes. Though interactive tasks such as adding users can't be performed in this way, scripts that simplify these functions can be created. The scripts can enhance the function and be tailored to meet the requirements of your environment. A few of the tasks that lend themselves to automation are process monitoring, file search and possible removal, and network distribution of files. Other tasks include those that can be simplified for users to perform or tools that add additional functionality to the Unix environment including sending jobs to a printer or generating usage reports for services.