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Solving ODEs on Linux

Many problems in science and engineering are modeled through ordinary differential equations (ODEs). An ODE is an equation that contains a function of one independent variable and its derivatives. more>>

Devops Linux Journal

DevOps: Everything You Need to Know

Have projects in development that need help? Have a great development operation in place that can ALWAYS be better? more>>

Tighten Up SSH

SSH is a Swiss Army knife and Hogwart's magic wand all rolled into one simple command-line tool. As often as we use it, we sometimes forget that even our encrypted friend can be secured more than it is by default. For a full list of options to turn on and off, simply type man sshd_config to read the man page for the configuration file. more>>

Security in Three Ds: Detect, Decide and Deny

Whenever a server is accessible via the Internet, it's a safe bet that hackers will be trying to access it. Just look at the SSH logs for any server you use, and you'll surely find lots of "authentication failure" lines, originating from IPs that have nothing to do with you or your business. more>>

Non-Linux FOSS: MenuMeters

It sounds like a "back in my day" story, but I really do miss the days when laptops had LED activity lights for hard drives and Wi-Fi. Sure, some still have them, but for the most part, the latest trend is to have no way of knowing if your application is pegging the CPU at 100%, or if it just locked up. more>>

Android Candy: Bluetooth Auto Connect

I love my latest Android device (see the March 2015 issue's Open-Source Classroom column for details), but for some reason, it won't automatically connect to my Bluetooth headset. When I turn on my headset, I want it to connect to my Android device so I can start using it right away. more>>

diff -u: What's New in Kernel Development

Nicolas Dichtel and Thierry Herbelot pointed out that the directories in the /proc filesystem used a linked list to identify their files. But, this would be slow when /proc directories started having lots of files, which, for example, might happen when the system needed lots of network sockets. more>>

Geek Guide: The DevOps Toolbox

When I was growing up, my father always said, "Work smarter, not harder." Now that I'm an adult, I've found that to be a core concept in my career as a DevOps engineer and manager. In order to work smarter, you've got to have good tools and technology in your corner doing a lot of the repetitive work, so you and your team can handle any exceptions that occur. more>>

Nmap—Not Just for Evil!

If SSH is the Swiss Army knife of the system administration world, Nmap is a box of dynamite. It's really easy to misuse dynamite and blow your foot off, but it's also a very powerful tool that can do jobs that are impossible without it. more>>

Resurrecting the Armadillo

1999 was a crazy year for business on the Internet, and for Linux. It was when Red Hat went public, with a record valuation, and VA Linux followed with a bigger one. Both were cases in point of the dot-com boom, a speculative bubble inflated by huge expectations of what the Internet would mean for business. more>>

March 2015 Issue of Linux Journal: System Administration

System administration is a very general term. It's our job to fix problems, repair systems and remind people to try power cycling their troubled desktops. more>>

High-Availability Storage with HA-LVM

In recent years, there has been a trend in which data centers have been opting for commodity hardware and software over proprietary solutions. Why shouldn't they? It offers extremely low costs and the flexibility to build an ecosystem the way it is preferred. The only limitation is the extent of the administrator's imagination. more>>

DNSMasq, the Pint-Sized Super Dæmon!

I've always been a fan of putting aftermarket firmware on consumer-grade routers. Whether it's DD-WRT, Tomato, OpenWRT or whatever your favorite flavor of "better than stock" firmware might be, it just makes economic sense. Unfortunately, my routing needs have surpassed my trusty Linksys router. more>>

Localhost DNS Cache

Is it weird to say that DNS is my favorite protocol? Because DNS is my favorite protocol. There's something about the simplicity of UDP packets combined with the power of a service that the entire Internet relies on that grabs my interest. Through the years, I've been impressed with just how few resources you need to run a modest DNS infrastructure for an internal network. more>>

Days Between Dates: the Counting

In my last article, we began an exploration of date math by validating a given date specified by the user, then explored how GNU date offers some slick math capabilities, but has some inherent limitations, the most notable of which is that it isn't on 100% of all Linux and UNIX systems. more>>

Multitenant Sites

For some time now, there has been tremendous growth in the world of Web applications. It's quite amazing to see what you can do just via a Web browser—not only can you buy just about anything, but also a growing number of sites offer "software as a service", often abbreviated as SaaS. The idea is that in exchange for a monthly service fee, you get access to a service. more>>

The Usability of GNOME

I work at a university, and one of our faculty members often repeats to me, "Software needs to be like a rock; it needs to be that easy to use." And, she's right. Because if software is too hard to use, no one will want to use it. more>>

Linux for Astronomers

I've looked at specialty distributions that were created for engineers and biologists in previous articles, but these aren't the only scientific disciplines that have their own distributions. So in this article, I introduce a distribution created specifically for astronomers, called Distro Astro. more>>

Elementary, My Dear Linux User

I suspect there are as many Ubuntu-based Linux distributions as there are all other distributions combined. Many of them are designed with a specific purpose in mind. Whether the desire is for a different looking desktop, custom kernel or just pre-installed packages, there's probably a version of *buntu out there to fit every need. more>>

Geek Guide
The DevOps Toolbox

Tools and Technologies for Scale and Reliability
by Linux Journal Editor Bill Childers

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