Friday round-up

by the editorial team

Here’s a few things we spotted on the web this week. As always, if you see something neat, let us know.

September 5th, 2008 |  No comments »
Tags: from the editors

Video: oVirt, part 1

by the editorial team

oVirt allows administrators to visualize what’s going on with their servers–whether they’re down the hall or entirely virtual. In addition to status checks, the tool allows easy management of virtualized space and computing resources. Listen as Hugh Brock and Perry Myers–both members of the engineering team that developed oVirt–discuss how it can help simplify IT organizations and reduce cost. Follow along as they demonstrate deploying and assigning hardware through oVirt’s graphical interface. » Read more

September 4th, 2008 |  1 comment »
Tags: multimedia

Tips and tricks: How do I re-enable the rhnsd service?

by the editorial team

With many Red Hat Enterprise Linux 4 to Red Hat Enterprise Linux 5 upgrades, the rhnsd service was disabled. To re-enable this service, perform the following steps:

# chkconfig --add rhnsd
# chkconfig rhnsd on
# service rhnsd start

September 3rd, 2008 |  1 comment »
Tags: tips and tricks

Q and A: MRG (Messaging, Real-time, and Grid)

by Bascha Harris

This past winter, Red Hat announced the release of a product called MRG–a computing platform that features high-speed messaging and allows high-throughput computing, realtime transactions, and workload management. Not sure what all that means? We weren’t either. So we contacted Bryan Che, the project manager for MRG, to see if we couldn’t get a few questions answered. He obliged, and so we bring you the MRG QandA. Still have questions of your own you want answered? Comment and let us know…

Red Hat has been working on the technologies behind MRG for quite some time–each of the components in MRG has had years of development. For example, Red Hat has been working on realtime technologies in the upstream kernel community for over seven years. Messaging has had a
similarly lengthy development history. Condor, the technology behind our grid scheduler, started development in the 1980’s!

We started work on these technologies because we saw the need for these capabilities, even if we didn’t know when or how we were going to bring
these technologies to market yet. For example, messaging is at the heart of enterprise computing. We had needs for messaging infrastructure at Red Hat–for building out our own capabilities around things like virtualization management. Many of Red Hat’s customers were asking us to provide an open source messaging offering. So, we started working on the AMQP specification and our messaging implementation, even though we didn’t know it was going to end up in something called “Red Hat Enterprise MRG”. » Read more

September 2nd, 2008 |  No comments »
Tags: Red Hat Enterprise Linux

Book review: O’Reilly’s Python for Unix and Linux System Administrators

by Robin Norwood

The title alone is a mouthful, but you have to love a book that knows what it’s about.

‘Unix and Linux Systems Administration’. We all know what that is. Balding, bearded, bespectacled wizards wearing t-shirts, nestled deep in a corporate office, on a floor the CEO and VP’s never visit, tapping out incantations day and night, feeding the temperamental beasts caged in the data center.

No? What about a growing group of dedicated, professional, hard-working experts who keep servers–and consequently the rest of the business–running smoothly? Sure, some of them may have less than a full head of hair, or wear the occasional t-shirt to work, but if your job (which you only call ‘System Administrator’ on your resume) involves monitoring and maintaining expensive hardware that performs critical business functions, and if the CEO only notices you or your group when things have going horribly, horribly wrong… then this is the book for you.

Back up a bit. How did ‘Python’ sneak into the title? This is a book for System Administrators–I mean, sysadmins. These guys write bash scripts to do their laundry. Sure, some of them may have joined the cult of Perl, and what proper Linux shop doesn’t have a zsh fanatic locked in the supply closet (in case of emergency)?

Unless you’ve been asleep at the keyboard for a few years, it’s hard to miss the rise of Python as a language of choice among web developers–along with old favorites Perl, PHP, and Java, and the new kid on the block, Ruby.

Perl is an old standby for many sysadmins, especially in those moments when you realize there’s a CPAN module that does 90% of what you need, or you’re tired of guessing whether brackets should go around the test condition in an ‘if’ statement. Is Python ready to take it’s place alongside Perl in a sysadmin’s toolbox? The authors of this book make an excellent case that yes, it is. » Read more

August 28th, 2008 |  No comments »
Tags: review

Tips and tricks: My system won’t boot from a burned CD

by the editorial team

Question: After downloading and burning ISO files from Red Hat Network (RHN) why will the system not boot from the first burned CD?

Answer:

First, make sure that you have downloaded the correct files. For each distribution there are binary files and source files. To complete an installation the four binary files for a particular distribution are required.

Simply burning these files to CD as files will result in a single file being burnt to CD with a .iso extension. If this occurs your disks will not be bootable. The files available from Red Hat Network (RHN) are disk images and need to be burned to CD as an image.

Your burning software will extract the files from the .iso and burn them to CD. See your specific burning software documentation for more information on how to burn images to CD.

To check if you have burned each image correctly, simply examine the contents of the CD. Instead of a single .iso file the disk should contain multiple files and directories. » Read more

August 27th, 2008 |  2 comments »
Tags: tips and tricks

Open source for the future. Art, music, and sustainablity at Monome

by Adrienne Yancey

My name is Adrienne, and I’m a graphic designer at Red Hat—I create meaning using type and image. The other day I stumbled upon a story involving music, sustainability, and open source. Needless to say, I was intrigued.

Brian Crabtree and Kelli Cain are the artists and creators behind Monome. At first glance, this cool device is simply a white square with a grid of buttons. It produces music and the buttons light up. It seems random, but the lights and music are synchronized.

Monome is a musical interface that connects to a computer–and is controlled by the applications the computer runs. It respond to the keys being pressed, and the LEDs light up–it is, at its simplest, a programmable controller for music, video, games, or art.

The beauty of an open process allows people to build on the idea, creating more than anyone could originally imagine (just like Fedora). People have manipulated Monome to do a number of things. » Read more

August 26th, 2008 |  4 comments »
Tags: culture, design, music

Tips and tricks: Alternative to mod_jk?

by the editorial team

Question: Is there an alternative module to the mod_jk module that is provided in the standard channel for Red Hat® Enterprise Linux® 5?

Answer: The module mod_jk is currently included as part of the Application Stack channel and is not available in the base channel. However in Red Hat Enterprise Linux 5, the package httpd does provide a module by the name mod_proxy_ajp which helps connect between the two. The configuration file is located at /etc/httpd/conf.d/proxy_ajp.conf. Edit this configuration file according to the needs of the enviroment. At the very least, add i the webapps directory used by tomcat:

     ProxyPass /tomcat/ ajp://localhost:8009/
     ProxyPass /examples/ ajp://localhost:8009/jsp-examples/

» Read more

August 25th, 2008 |  No comments »
Tags: tips and tricks