Archives For Linux

CentOS 7: kernel

Terrence T. Cox —  December 15, 2014

Along with all the requisite package and application upgrades that came along with CentOS 7, probably the largest upgrade was the move to the Linux Kernel 3.1 tree. This is a pretty big change for the Enterprise from the venerable 2.6 kernel version that was largely considered the most stable version ever. In this article, we are going to take a look at some of the key changes from the CentOS 6 kernel and the new CentOS 7 kernel.
Continue Reading…

We have covered virtualization at length both in this space as well as at Linux Academy in the past. However, we have always been focused on hardware virtualization through a Hypervisor. Full OS emulation and server stack with device drivers communicating directly within the virtualization stack. Along comes Docker to further application virtualization. Although similar technologies have existed for some time (since early 2000), Docker appears to have arrived at the right time and captured all the buzz. Let’s take a look at some of the Docker basics that we will be covering in this exciting new course! Ready to jump strait to the course?

A Brief Introduction
So let’s talk for a few minutes about what exactly Docker is. Well, let’s start out with an explanation taken largely from Wikipedia as well as from the Docker Website itself.

Docker is an open-source project that automates the deployment of applications inside software containers, by providing an additional layer of abstraction and automation of operating system-level virtualization on Linux.

So having said that, its a collection of tools that package an application and everything it depends on into a “container” that virtualizes the application so it can run on any compatible OS (and by compatible, we mean Docker compatible, which is pretty much anything).

Continue Reading…

Multimedia on Linux has gone from being a giant pain to being more powerful than any other operating system, including the vaunted Multimedia powerhouse Apple OSX. One of the most valuable tools in your Linux Multimedia arsenal is a great conversion utility called Handbrake – and like all the best Linux utilities, it’s free! Let’s take a look at getting it set up for our use.

Download and Installation
Normally I would gloss over the download portion of our article, but if you just do a Google search looking for Handbrake, the first couple of pages are littered with fakes, download managers and other places that are at best redistributing Handbrake and at worst installing who knows what on your PC. The only OFFICIAL place (other than your distribution repositories, which tend to run a bit behind the latest stable version) to get this utility is at the Handbrake website. Make sure you pick up your copy from here.

Continue Reading…

(OpenStacks Identity Service)

OpenStack Identity (Keystone) provides a central directory of users mapped to the OpenStack services they can access. It acts as a common authentication system across the cloud operating system and can integrate with existing backend directory services like LDAP. It supports multiple forms of authentication including standard username and password credentials, token-based systems and AWS-style (i.e. Amazon Web Services) logins. Additionally, the catalog provides a queryable list of all of the services deployed in an OpenStack cloud in a single registry. Users and third-party tools can programmatically determine which resources they can access.

In OpenStack before we can start utilizing the the vast ecosystem of services and applications that are available ie: (Nova, Swift, Neutron, Glance, etc), we first have to authorize our users.  There are some very important terms that we need to understand when working with OpenStack Identity (keystone).

I would like to take a moment to address one of the biggest confusions when setting up endpoints in keystone today.  First let’s start out by defining what an endpoint even is.  An endpoint in keystone is just a URL that can be used to access a service within OpenStack.  An endpoint is just like a point of contact for YOU (the user) to use an OpenStack service.  The adminurl (we will show these further down) is for the admin users, the internalurl are what the other services use to talk to each other.  And the publicurl is what everyone else accessing the service endpoint uses.
Continue Reading…

Although there is a plethora of Source and Revision Control options around today, only one was created by our favorite Linux author Mr. Linus Torvalds and that would be Git. Right here, we are announcing the availability of the course called Git and Gitlab: From Start to Finish so sign up or sign in and wade into the deep end of the pool.

Git Basics
We will start out this course of more than 24 videos with the basics of using Git for your revision control activities. Whether you are working with local repositories or a Git server remotely, you will get a feel for the following topics:

At the Linux Academy, our goal is to create not only the best content to help you pass your Linux and Cloud certifications, but also the best tools to help you stay engaged and focused. Our content has always been self-paced, but we’ve had a different spin on it. At the Linux Academy, we’ve always made our instructors available to the students, much like if you were sitting in the same room as an instructor. Really, we wanted classroom learning intimacy to be the same in a self-paced online environment. One of the main advantages of classroom learning is that it is not self-paced. In fact, you either keep up or you lose out. We wanted to imitate this same type of environment without the harsh “you lose out if you get behind”. We spent the last 3 months researching, speaking with users, and developing a new tool called “learning plans”.

Linux Academy Learning Plans

Learning plans are an original take on self-paced learning developed at the Linux Academy. They allow you to take self-paced and make them “scheduled”. Simple questions like “how long should I study” or “when should I be expected to complete the course” are now obsolete questions due to the Linux Academy learning plans. Really, it’s as simple as filling out a simple wizard page that asks for your start date and availability, then our system does the magic. It uses our algorithm, based on suggested study times, content length, and extra study requirements to develop the perfect study plan for you. It also works hard to keep you on track. It measures your progress, provides daily items due, and even sends you reminders when it’s time for you to study. If needed, you can adjust your learning plan or even pause it, so if life happens you don’t lose out on your studies. The Linux Academy learning plans remove those unknown stresses and extra time needed to manage your own personal study plans and automates it to help you be successful even if you don’t have much time at all to study.

Only 20 minutes a day? Maybe one hour a week? That’s ok, let our learning plans help you make the most of that one hour a week!

Not only have we just announced our learning plans, but we also announced the availability of FOUR real servers for each user to use as part of there Linux Academy account. We also announced the immediate availability of multiple courses including more Linux, DevOps, and OpenStack topics! The best part of all this is the content and features were added to the Linux Academy without any type of price increase. You’re able to have access to over 800 videos, 150 quizzes, scenario based labs, study guides, and your four real lab servers for only $25/mo (or less if you purchase quarterly or annually).

CentOS 7, along with Kernel, Desktop, package and application changes galore, has taken the “Fedora” and “Debian” plunge into the deep end and converted daemon and service management from the older “service or /etc/init.d” paradigm into the “systemd” end of the pool. If you are a modern Linux Desktop user on a daily basis, you may be completely familiar with that method, however, it is a pretty large change for those administrators coming from the longevity associated with Red Hat and CentOS’ use of the ‘service’ method of management. Let’s take a deeper look at the new way of doing things.
Continue Reading…

Video isn’t the only media that Linux has made great strides in. Linux is routinely used by big sound and recording studios to record, mix and treat sound for movies and television. Although those tools can be expensive to own, the average user still had a plethora of utilities available that do many of the same things. Let’s take a look at one of the more popular overall sound packages called Audacity.

Download and Installation
In this case, the set up couldn’t be easier. As long as you have a functioning sound card/chip/USB speakers, then your distribution already has everything needed to work with sound except Audacity itself. Easy enough to rectify, let’s pull it down:
sudo apt-get install audacity
sudo yum install audacity

Continue Reading…

Like our series of ongoing articles on Ubuntu 14.04 LTS, we are starting a series of articles on the recently released CentOS 7 distribution. Unlike Ubuntu, new versions of CentOS take years in between major versions. CentOS also supports their major releases for quite some time (see the table below). This first post will introduce some of the major changes to CentOS at a high level and then over the next month or so, we will discuss many of these changes in more detail. Let’s get started!

CentOS Support Timeline
Just as a quick overview, let’s take a look at the support life of each of the last major releases of CentOS (in general, seven years from release date):

  • CentOS 5.x – End of Life 03/31/2017
  • CentOS 6.x – End of Life 11/30/2020
  • CentOS 7.x – End of Life 06/30/2024

Continue Reading…

I’m excited to finally announce, The Linux Academy Show and Giveaway! During this special show we will be giving out FABULOUS PRIZES! To enter, check out the giveaway details.

Prizes aren’t enough? Well wait, theres more!
We’ve been working on some new and previously unmentioned content that is sure to delight and surprise you!

Sill not enough? We’ve got some BIG features we’ve been working on that you won’t find anywhere else!

♬ It’s time to play the music! ♬
♬ It’s time to light the lights! ♬
♬ It’s time to win some prizes on the Linux Academy Show tonight! ♬