Issue #220, August 2012
One of these things doesn't belong in the workplace. If you ask most people in the business world, they'd say a penguin is a silly thing to keep at work. Those of us in the server room, however, just snicker at such foolishness. I'll take Linux over a committee meeting any day! This month, we get to see Linux at work.
You might have noticed the past few months we've chosen a product or program as "Editors' Choice" for the issue. It's a great way for us to highlight something we find particularly awesome. This month, I introduce Resara. Samba 4 has been in active development for years, but the folks at Resara package the current build into a very functional Microsoft Active Directory replacement. Their community version is full-featured and free—it's definitely worth checking out.
Reuven M. Lerner talks about a particularly serious issue this month, as he discusses database integrity. Databases often are overlooked as boring, but we rely on them constantly. Having viable, accurate data is something we assume, but Reuven shows us how to make that assumption possible. Dave Taylor follows up with a tutorial on how to use shell aliases and functions. We often take the simple tweaks in our .bashrc file for granted, but Dave not only opens it up, he also shows how to add tweaks of our own.
The Raspberry Pi device is something most people in our circles are familiar with, even if we haven't been able to get our hands on one! Kyle Rankin, as usual, takes something awesome and makes it even more so. Combining his Nokia N900 and the Raspberry Pi, Kyle is able to interface directly with the fancy new device. Whether you're interested in creating a super-efficient media center or just like playing with embedded devices, Kyle makes it simple.
My Open-Source Classroom column this month is all about smoke and mirrors—without the smoke. Although certainly not practical for everyone, sometimes having a local repository mirror is useful. I explain how to mirror CentOS and Ubuntu. Be sure to bring lots of storage space!
When we think about compression, it usually means archiving or resource conservation. Arun Viswanathan discusses LZO compression in Hadoop this month, which uses saved space to decrease disk read times. Since LZO can be decompressed very quickly, the advantages in data transfer times are significant. Arun has code samples and usage examples that really show off the benefits.
Jay Palat found a Vagrant he really likes. If you've ever deployed an application only to have it work on some systems but not others, you'll likely agree with him. Vagrant is a tool for providing a virtualized development environment so you can test applications on multiple systems without actually creating the entire test environment. It's certainly possible to virtualize different types of installation environments, but Vagrant allows you to test those environments with a single tool.
Linux has a great virtual filesystem layer that allows the seamless use of underlying filesystems. Most people don't know that Samba does the same thing for its fileshares. Richard Sharpe shows how to set up Samba VFS Modules, giving us the advantages of different filesystem features via Samba shares. Richard guides us through an example that really shows how to leverage this little known feature of Samba.
Cloud computing is here to stay, and while the terminology and concepts are new, our needs as end users haven't changed very much. Andrew Fabbro teaches us to use Tarsnap, which uses familiar command-line commands to manipulate tar files in the cloud. Amazon S3 and EC2 are the de facto standard for cloud-based computing, and Tarsnap allows manipulation of Amazon services using the handy-dandy command line. If you manage cloud services, you'll want to check out Tarsnap.
Doc Searls ends our issue this month, which is usually how our magazine ends. This time, however, he shares a chapter from his new book The Intention Economy, which is a brilliant piece on free markets and the Internet. Are we slaves to Internet companies? Does the Internet work for us, or are we slaves of on-line captors? Be sure to read the excerpt, and be sure to enjoy this entire issue of Linux Journal. Whether you're interested in new products, coding examples, tech tips or cool projects, this issue aims to please.