Jun 242014

A not so common guide, article by   first posted on http://www.refining-linux.org

The UNIX philosophy is based on the DRY principle which declares: “Don’t repeat yourself”. Therefore, a program just does what it’s made for and uses libraries or even other programs on your system to do a more advanced job. Some of these auxiliary programs are user definable and probably you already know the EDITOR environment variable, which specifies your default editor for the console. This is used, e.g., for the command visudo, which opens your /etc/sudoers file safely, or by svn to input a commit comment. But another important component is your console pager, which is used to display textual content on the console.

As a system administrator or a more advanced Linux user you surely know man and how to use it. man shows you the (probably localized) contents of your system’s manual pages for a specific command or file, at least you might think so, but actually that’s wrong or let’s say: not completely the truth. man selects which manpage to show, but the display itself is managed by your pager. Of course, not only man makes use of the pager, also commands like mail use it (which might not exist on your system if you don’t have an MTA installed), so this is a very basic program.

I assume, you have already used your pager very often, which is nothing else than more, less or lv (which is also a good pager but very seldom installed by default and therefore rarely known). Most of the time, you use them to display the contents of log files or configurations, which you don’t want to alter, but that’s not all. As mentioned before, other programs use your pager as well and there is a way to configure which one to take and of course also how to use it.

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Jun 292013

Sometimes it’s useful to do a step back and think at the way you are doing your daily tasks and in general how you approach your work, if you are interested in this topic I suggest also the great book “Time management for system administrator

This was written by Jennifer Davis and first published on http://sysadvent.blogspot.it/

For most of us, the end of year brings performance appraisals and reflection on the year’s setbacks and accomplishments both professional and personal. In the glass bowl of life, I ask myself if I’ve made a difference, earned respect, have I grown from where I started the year? Technology has brought us innovation to hack our lives and measure our personal success through metrics. For example measuring sleep, weight, and activity. For example, I can see how much I slept, how fast I biked to work this morning, how often I biked, and the steps forward (or back) towards my goals. There is a dearth in tools available to measure personal work growth and effectiveness.

Being an effective system administrator requires an ability to do several (seemingly obvious but often rather fraught) things: To break down projects into actions that we understand as a part, as a whole, and can manage in a discrete period of time; explaining this roadmap to other teams; and successfully keeping implementation on schedule while being flexible enough to handle any issues that arise. The job descriptions and responsibilities of system administrators can vary greatly in scope and the corresponding degrees of difficulty and creativity necessary to succeed. Since “system administrator” alone can sometimes function as a vague catch-all for such a diversity of tasks and functions we use a variety of sometimes unwieldy names to better specify our roles and focus. Regardless of title there is a great deal of commonality in how teams we work for/with view us and depend upon our knowledge and skills. In some cases it’s a bit like being a member of a symphony in which the strings, the brass, and the wind sections cannot agree upon the tempo or even what piece to play.

At a team level, management has a vision of what the team should be doing and how it should be working. Often our work is considered a cost center, something that doesn’t produce a direct profit and is generally first in line for cuts. Management becomes focused on the bottom line to the detriment of building a strong team and an encompassing vision. Teams are put in the unfortunate position of competing for finite resources. For better or worse, the team that “markets” itself best generally comes out ahead.

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Jul 142012

If you are a system administrator and you want to push the performance of your PHP website such as Drupal, WordPress or wrote by you or other programmers, there are good chances that you’ve heard about the Alternate PHP Cache or simply APC.

The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. Its goal is to provide a free, open, and robust framework for caching and optimizing PHP intermediate code.

That everything you’ll read about APC on the php.net site, and i think is not enough in comparison to the huge boost of performance that this small component can give you, for some quick facts check the tests done by Guillermo Garron on his website.

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The broken dreams of a Linux system administrator

After some studies, or perhaps a specialist course or presentation you’d like to start to implement in your company the best practice you have learnt, and perhaps start a new and better era for your IT department. But it seem that something always go in the wrong way or there are unexpected difficulties that make [...]

Check your disk usage with df and du

As system administrator , but also as common user on my PC, one of the more common problem is when a file system got filled up at up at 100% of its size. So, in this article we’ll see 2 commands that can help us in keeping under control or check the space used in [...]