Focus: System Administration
In this issue we have a bunch of articles on system administration, so if you're thinking of breaking into this exciting career, where the stress is high but the hours are long, now is a perfect time to pull up a spare Linux box and get started.
Replacing one big UNIX server with a rack full of inexpensive Linux machines sounds like a great way to save money and increase your server application's reliability and performance. But if you're interested in setting up a high-availability Linux cluster, have a look at how well your clustering technology of choice handles the four failure scenarios in Tim Burke's “High Availability Cluster Checklist”.
While we're on the subject of clustering, those of you interested in pushing the envelope on Linux cluster performance will want to read Ibrahim Haddad's article on the Parallel Virtual File System. Don't try it on the accounting department's server, though—PVFS is about speed, speed, speed and doesn't offer the level of redundancy they're probably expecting.
One of the first concerns for anyone starting out in system administration should be making backups. In “A Linux-Based Automatic Backup System” Michael O'Brien explains not just how to back up your Linux systems but also how to run a script on your Linux system to back up files on your legacy Microsoft Windows machines.
J. R. “Bob” Dobbs tells us that “Too much is always better than not enough.” And that certainly goes for scripting. Marcel Gagné takes scripting to the extremes with an introduction to Expect, the tool whose motto is “Curing Those Uncontrollable Fits of Interactivity”. When you want to write scripts to do everything, you might run into a brick wall—a program that tells you to navigate a menu or enter a command. Instead of giving up and doing it manually, write an Expect script to bend it to your will. You are the sys admin, you are in control, not the machine, not the software, you.
Last month, we complained that APC has not yet published the protocol for communicating with their UPSes. Fortunately, Riccardo Facchetti has figured out how to talk APC-speak—whether APC likes it or not—and so those of you with APC UPSes can safely shut down when the UPS is drained. It's long, but worthwhile reading if you want to protect your whole network from power outages. I'm running apcupsd at home now, and it works great. One important tip: don't forget to check what kind of serial cable you're using and put it in the config file.
You might tend to think of port scans and such as tools for breaking into a network, not for administering it. But read Lawrence Teo's article and try running one on your own network some time. You might find compromised hosts participating in a distributed denial of service attack, improperly configured systems, or just some weenie who decided to put a “personal web server” to serve out stuff that you don't want public.
If you have a system administration idea that works for you, please let us know. We might just want you to write an article about it, and when you send it in, you can hear somebody say, “thank you.”
—Don Marti, Technical Editor
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.Register Now!
- SUSE LLC's SUSE Manager
- My +1 Sword of Productivity
- Managing Linux Using Puppet
- Non-Linux FOSS: Caffeine!
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Tech Tip: Really Simple HTTP Server with Python
- Doing for User Space What We Did for Kernel Space
- Rogue Wave Software's Zend Server
- Parsing an RSS News Feed with a Bash Script
- SuperTuxKart 0.9.2 Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide