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RHEL 7 supports Docker containers, systemd, Microsoft-compatible ID management, and XFS for 500TB filesystems
The biggest new addition to RHEL 7 is tight integration of Docker, the explosively popular application-virtualization technology. With Docker itself hitting 1.0 status, the timing on RHEL 7 couldn’t be more fitting.
Apps packaged by Docker are isolated from the system and from each other, so they can be moved between systems and still run as expected. RHEL 7 is meant to be able to use Docker as efficiently as possible so that apps don’t contend for resources or get confused about which edition of a runtime to use.
Long-term plans on the road map for Docker in RHEL involve possibly breaking the OS itself into a series of Docker containers, allowing as little or as much of a system to be deployed as needed with minimal overhead. Dubbed “Project Atomic,” the initiative is still in the early stages, with Red Hat planning to deploy it first via its Fedora Linux distribution, nominally used as a testing ground for cutting-edge technologies.
The inclusion of the systemd process manager may spark controversy among system administrators and Linux mavens. Systemd was developed to replace the init system in use since the days of proprietary Unix, and it allows, for example, more efficient loading of services during the boot process.
With systemd as a potential sore spot, Red Hat has not rushed in to add it. Fedora has included systemd as a default since version 15, released in 2010, giving Red Hat good experience with how systemd behaves in the real world. Also, systemd isn’t joining RHEL 7 arbitrarily, but as part of larger plans for the OS. Red Hat wants to enhance the way Docker containers are supported in RHEL 7 by using systemd, for example.
3. XFS by default
A third major change, though not likely to raise nearly as many eyebrows, applies to the default file system used by RHEL to XFS.
Originally created by Silicon Graphics International, XFS has long been in production use with Linux systems, and on RHEL 7 it’ll support file systems of up to 500TB in size. RHEL 6 used ext4 as the default, although it shipped with XFS as an option. Red Hat competitor Suse Linux also supports XFS, although it defaults to ext3 on installation.
Unfortunately, there’s no real way to migrate from other file systems currently in use on RHEL — such as ext4 or btrfs– other than backing up and restoring.
4. Microsoft-compatible identity management
Even admins who aren’t fans of Microsoft Windows have a grudging respect for Microsoft Active Directory. RHEL 7 improves the way RHEL deals with AD by adding two key new features. Cross-realm trusts can now be established between RHEL 7 and AD, so AD users can access resources on the Linux side without having to go through another sign-on step. The other big AD-related addition to RHEL 7, realmd, automates both the discovery of AD (or other Red Hat identity services) based on DNS information and the process of joining to it.
5. Performance Co-Pilot
Performance tuning without live statistics is like driving with the windshield painted over, so RHEL 7 introduces a new performance-monitoring system PCP (Performance Co-Pilot), originally created by Silicon Graphics International but now available as part of RHEL 7. In addition to monitoring and recording system stats, PCP sports APIs and a tool set for making that data available to other subsystems, such as — you guessed it — the newly introduced systemd.
Another minor addition in this vein: new performance profiles. RHEL 6 already had performance profiles, which are ways to tune RHEL overall to meet specific usage scenarios. RHEL 7 not only defaults to a new profile that emphasizes maximum throughput performance, but includes another new default profile for balancing performance against energy savings.
With all the changes coming with Red Hat Enterprise Linux (RHEL) 7 and the training around it, I’ve heard Red Hat admins ask, “But what about their certifications?” The reality is that not much has changed around Red Hat certifications at the basic levels. But if you’ve got your sights set higher for the RHCA and some of the specialty areas, things have changed a bit!
At the lower levels — Red Hat Certified System Administrator (RHCSA) and Red Hat Certified Engineer (RHCE) — nothing has really changed. You still need to take the same courses and exams (EX200 for the RHCSA and EX300 for the RHCE), and you’ll need both of these certifications to get your Red Hat Certified Architect (RHCA) certification. Continue reading
How can understanding Linux enhance a career? This question is interesting because there are two drastically different answers. The first is the obvious answer that you can find through websites and studies everywhere, but the second is a little more subtle. And a lot more awesome.
You might be reading this post because you read articles like this one from The Linux Foundation regarding hiring demands for Linux experts. Or perhaps you read the 2013 report and realized there’s a trend for hiring Linux professionals. Basically, if you want a job in technology, being a Linux expert is like finding a golden ticket in your Wonka bar.
But what about non-Linux experts who are professionals in their own fields? Does the unemployed or underemployed Microsoft administrator have to start over and look for an entry level job in a field they don’t know, with zero experience and almost zero enthusiasm?
Let me start by telling you about my last job. This is part six of the blog series, so by now you probably realize that I’m a Linux guy, and couldn’t hide it if I tried. But my last full-time position? Managing director of the database department at a private university. This university was Microsoft-centric and all of our database systems were Microsoft SQL. We had proprietary Windows applications running on a large array of Windows servers. There wasn’t a single Linux operating system in the entire IT department. (Well, except for the Xubuntu VM on my laptop, but that doesn’t really count)
How on earth did I get that job when my resume screams Linux and Open Source? It’s simple: because working with Linux forces you to be a thinker.
My boss (an incredible man, and now a great friend) saw the Linux stuff on my resume and didn’t think, “This guy doesn’t know Microsoft stuff at all!” Rather he saw it and thought, “This guy knows Linux? He can do anything!”
Sure, that’s a generalization, but it’s pretty common. It’s also often the truth too. Being comfortable with Linux means that you’re flexible. There are tons of Microsoft-only server rooms, but in an office environment, there’s rarely a Linux-only server room. That means Linux users have to be comfortable working with multiple operating systems. It also means they tend to have incredible troubleshooting skills, and by their mere interest in Linux, it shows they can (and do) think outside the box.
So how has Linux helped my career? It helped me land a job at a university that doesn’t have a single Linux server in their entire infrastructure. Linux professionals don’t just fix computers, they solve problems. That’s what makes them so invaluable.
How can Linux change your career?
Yes, I’m about to get a little grandiose. But I’m passionate about changing people’s lives, and I’ve seen it happen, so at least consider this list of ways Linux can help your career.
- Quite simply, you can get a job. Obviously, there are many, many places looking for individuals who are skilled with Linux. The links above will attest to that. But that’s just the obvious answer.
- Learning Linux helps you look at your skillset in a different light. No longer do you see yourself as a list of certifications and abilities, but rather a forward-thinking problem solver. All of your skills are just arrows in your quiver, and your brain is what makes you so valuable. Remember, a Google search can teach you how to install an Apache server, but only a well-trained problem solver can know when it’s appropriate to do so.
- You can find a job you love. Once you realize how valuable and flexible you’ve become, you can focus more on finding a job you love. We all need to pay our mortgage, but if your job options are broader, the chances of finding your calling are much greater.
- You can offer employers or clients well-rounded advice. Remember from past blog posts, there are times Linux isn’t the right choice. The only people who will be able to tell the difference are those familiar with Linux and the alternatives. Your Linux expertise can be invaluable to someone who is implementing a SharePoint infrastructure. Should they be using Linux-based solutions instead? Be that person who can help them decide. Your rewards will be more than just monetary. I promise.
- Reread number 2. Truly, making the mental shift from a technician to a solutions provider is the key to success in IT. Be the answer that a Google search can’t provide. You don’t need all the answers; you need to know how to ask all the right questions.
I’m excited about the future of technology, and the future Linux professionals will play in it. It’s certainly not too late to jump into the mix and start learning Linux. As the hiring focus shifts more and more toward DevOps type skills, a Linux skillset (and more importantly an open source mindset) will be the types of things that will make you very employable. Even more important than that, however, is that it will likely leave you a fulfilled person. At the end of the day, that’s the key to a successful career.
Interesting Infographics for Linux Enthusiasts & Lovers
Information graphics or infographics are graphic visual representations of information, data or knowledge. These graphics present complex information quickly and clearly, and are easy to understand. Infographics are sources of interesting information, when you are in need of some. Reading boring, long, colorless articles isn’t so attractive and interesting than reading and viewing facts and numbers in an illustrated way. Not only an illustrated way, but a very creative, attractive and super-appealing way.
(Click on images to Enlarge )
An infographic on the history of Linux.
Click on the infographic to view a larger version
Source : BlogSearchEngine
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