Have you ever wondered how CentOS and Red Hat Enterprise Linux are related?
Well, in this episode we have you covered, stay tuned.
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Hello and welcome to another exciting episode here at ITProTV,
this is your Linux essentials series.
And in this episode we're gonna be talking about RHEL and
CentOS, joining us is Don Pezet, how's it going Don?
>> It is going great, I'm ready to jump in and
talk about some of my favorite Linux distros today.
So we're gonna be learn a little bit about the history of Red Hat Enterprise Linux
and CentOS the Community Enterprise Operating System.
We'll talk about how those are related and some of the information you
need to know to determine which one is right for your environment.
>> So Don, Red Hat is one of the few commercial Linux distros out there,
how did that come about?
>> Well, it came about because there weren't any others out there at the time,
so Red Hat has actually been around a long, long time.
And in the very beginning of Linux, we have to remember that Linus Torvalds
wrote that kernel and he gave it away for free.
And then a couple of distributors, they took that kernel,
packaged it with GNU tools and a handful of other things and created, Slackware and
Debian and the other early distros, and they gave those away for free.
Now, as a end user, a free operating system has a lot of
value- >> Right?
>> -For being free, because it saves you money, you don't pay, but for
a company, there's a big risk.
Because as a company, if you're about to deploy a bunch of desktops or
a bunch of servers, well, Apple is behind macOS, Microsoft is behind Windows.
You've got these multi billion dollar companies that are there, backing it up,
giving it support, giving you stability, you can sleep at night knowing that
company is most likely going to be in business tomorrow.
>> Yeah.
>> Meanwhile, if you take a free distribution like Debian,
you don't really know if it's gonna be around tomorrow or not.
They run on donations, and in the early days, they didn't get a lot of donations,
it was really volunteer hours, so there's a ton of risk.
But, the executives over at Red Hat, they saw the writing on the wall,
they said look, Linux is an amazing platform.
One day it's going to be the de facto server platform,
even on the desktop it's really, really good back then it was really okay.
>> [LAUGH] >> It's come a long way, believe me.
>> Right. >> But they said look, there's this risk,
that if you deployed and something goes wrong, you don't have anybody to ask.
So let's start a company, and make a company where we take a Linux distro,
just like everybody else, but we try and make it as stable as possible.
We don't take risks, we don't deploy cutting edge things,
we deploy things that we know are stable.
And then we have a staff of technical support engineers, that are ready to
answer that phone and help people out and give them the aid they need.
>> So remind us is Red Hat a one from scratch or
did they take another set of code from somebody else and then build off of that?
>> So technically they are built from scratch.
>> Okay. >> So they use the Linux kernel, but
hand select all tools, and they have to.
>> Yeah. >> Because pretty much
all the other distros move ahead really fast, they roll out changes really fast.
And Red Hat isn't about doing the latest and
greatest technology, they're about doing the most stable technology.
And so that puts them behind other people and for an end user,
that can be frustrating, it might seem like a bad idea.
But if your business relies on it, it's really a valuable thing to have, so
in the Red Hat world it is really about stability and that's what you pay for.
That's why it's not free like the others, you're paying for the support,
the testing,
the stability, those are the key aspects of why that's a commercial system right?
But it is still an open source system, so that means they're using the Linux kernel,
they're covered under the GPL and all the other various licenses that are out there.
So when they create something, when they write that change or update or
make the kernel better, they take that and they send the changes back upstream.
So that they can be incorporated into the Linux kernel and
they publish the source code so that anybody can get it.
So, for example, if you wanted to run Red Hat but you didn't wanna pay for
it, well, you could go and
download the source code because they have to publish the source code.
And you could compile it yourself, and effectively install RHEL,
Red Hat Enterprise Linux, they call it RHEL.
>> Yeah. >> You could install RHEL without having
to pay for it, in fact, there's some distros that do that like CentOS.
Where that's effectively what they do is they take the Red Hat code,
they compile it up to create that that system.
So it's tough if you wanna try it but
you can because it is still rooted in open source.
>> Could you give us a little background on CentOS since that's the other thing
we're talking about in this episode?
>> Yeah.
So CentOS is another distro that's out there that's a very, very, very popular,
in fact, I would say it's even more popular than Red Hat.
Even though it's technically descended from Red Hat.
>> Yeah. >> And
what's going on there is that CentOS,
the name stands for Community Enterprise Operating System.
And the enterprise is a reference back to Red Hat Enterprise Linux,
that RHEL is commercial, it's held behind a pay gate, you got to pay to use it.
Well, CentOS takes that commercial enterprise operating system and
makes it free.
So anybody can go and download CentOS from their website centos.org,
you can download it, and you'll have that access to it.
In fact, here let me pull up the web page, so
I've got the Red Hat Enterprise Linux web page pulled up right here.
And so you'll see where they've got a great big, try it for free
where you can get a demo, I think it's like 68 demo, or you can buy it right?
So that's that big purchase side.
But if we jump over to the CentOS page, it's a little bit different
because there's just a great big Get CentOS Now button.
And when we click on that, I can download the ISO and I can go and install it, and
I never have to pay them a dime.
They work entirely based on donations and
there's a number of different organizations that fund them.
Amazon, Amazon Linux is actually based off of the CentOS releases, and
so Amazon pumps a good bit of money into CentOS.
So that's how they're able to stay afloat even though they don't
offer things like support, so a very different basis there.
But what CentOS is effectively doing is taking that Red Hat code and
they sift through it, they look for anywhere there's the Red Hat name
because that's trademarked, so you got to take that out.
They locate any logos that are in there, any graphics, that are trademarked or
copyright or whatever and they take those out.
And once they've got it all cleaned from a copyright and trademark standpoint,
they recompile it, and once they do, it's then compiled into CentOS.
Now, if you go and download it, you'll notice.
So if I go to download it and I start looking at the images that are being
released here, I can see their version numbers and the version numbers,
it's actually kind of small, isn't it?
So this is CentOS version 8 that's available right now,
that's the current one, the version number is typically the same
as it is over in Red Hat in fact there's two here, let me show you a different way.
So the machine that I'm on right now, this is a Red Hat Enterprise Linux machine.
And so if I go into my settings and my details, let me just pull this up here.
I can see that I am running Red Hat Enterprise Linux, whoops.
8.1 right, so I'm on version 8.1.
And that's the latest as of the filming of this episode.
So meanwhile I have installed on my other machine right here, this is CentOS okay?
And when I go to login to sent to us and pull up that same information,
assuming I've applied all my updates, this should be CentOS 8.1 as well.
Now, the version numbers are almost always identical because they're being built off
of the same source code right?
But If Red Hat releases 8.2 today,
it might take a few weeks before CentOS releases 8.2.
And that's because they have to sift through it and
get all the other copyrights and things like that out of there.
And in fact, looking at mine,
I can see that this is actually just running CentOS 8, not 8.1 yet.
So that change hasn't transitioned over to this machine yet, or
I've fallen behind on my updates, I might need to do my updates here.
I guess I could check from here but what you'll find, is that not
only are they typically the same version, but they pretty much look the same, right?
Let me go back out here.
And I'm going to log out of both of these machines.
And I'll just kind of show you the experience of what an end user would have.
They were switching from one machine to another.
So I'm gonna log out of that one, and let me get over here to Red Hat and
I'll log out of it.
So even just comparing the logout screens or the login screens,
you'll immediately see the comparisons.
>> Very similar, exactly the same pretty much.
>> Yeah. >> [LAUGH]
>> See that Red Hat logo down at
the bottom of the screen.
>> Yeah. >> If I jump back over to CentOS.
>> Is now a CentOS logo.
>> Yeah. >> Right.
So they are effectively the same, and that's really nice
because if you're a student or somebody learning, you can deploy CentOS.
And then when you go to an enterprise and work and they say, yeah, we run RHEL,
no problem, you know how to do everything.
Everything's the same so you snap right into it, or if you're deploying a scalable
cluster in AWS, you can use CentOS because you have to pay for a license for
each node that you spin up.
They're all free.
But then if you have a database server that you need rock solid support for,
you can run it on top of RHEL and now you can call, canonical-
>> [LAUGH]
>> -Call Red Hat for
support and, IBM now they've acquired Red Hat and get help from them.
So it's really nice having that kind of flexibility and options there.
And Red Hat actively contributes to CentOS.
So this isn't like a CentOS is sneaking behind their back kind of thing.
It's something that they support they provide that, channel and
a lot of the contributors to CentOS are actually Red Hat employees.
>> So, CentOS is free, it's based on Red Hat is it?
People use Red Hat and buy it because?
>> Okay, so this is a common
question like- >> Yeah.
>> -If I can get it for free- >> Why would I get the other thing?
>> -Why would anybody?
>> Yeah, >> Right.
Well, I've already said one reason that's support.
>> Yes, yes. >> Right, if you need somebody to call and
get help with, that's a big part of it.
But, Red Hat does a lot more than just Red Hat Enterprise Linux, right?
There was a time, say 20 years ago when, or 15 years ago maybe,
where Red Hat just had RHEL, and that was it.
They just had Red Hat Enterprise Linux, and
it was kind it was just called Red Hat Linux.
Well, now they've diversified, and they have a ton of other products.
That are all designed to run on top of RHEL.
And when you run those other products, like OpenStack or Kubernetes, or something
like that, and you run that on top of RHEL, well then Red Hat will support
the entire stack all of the software you're running on top of the hardware.
So any type of software problem you have, you can go to them for that assistance.
And you know they're testing it and it's stable, and
there's some things that they do that are not open source.
An example of that, let me see I had the web page open a minute ago, but
I'll pull it up.
They have a product called Red Hat Insights.
And Red Hat Insights is something that you install on your Red Hat machines like
your servers or desktops or whatever, and they report back to a central location.
And as a network admin, I can log into this one panel.
And I can see any alerts that are being generated across my entire environment.
And it can even remediate some of them, it'll say like, hey, here's this problem,
just click this fix it button and it'll fix it.
It actually said mitigate, and so it'll mitigate the issue and correct it.
That's really cool.
That relies on Red Hat servers.
And it's not open source.
So if you want to use that you've got to have the commercial version of RHEL and
then you gain access to that.
So there's a lot of really good reasons.
Service and Support is one part of it, but support for their other products and
there's a lot like the JBoss, OpenShift, their various runtimes,
all these things that run amazingly well and stable right on top of RHEL.
That's their big claim to fame.
>> Okay >> But
if you're just looking for Linux, and that's it.
CentOS is a great fit and I actually encourage people who are getting ready to
support Linux in the workplace to learn CentOS
because it gives you an easy way to move back and forth.
A lot of users will prefer a Ubuntu because it looks prettier-
>> It does look pretty, I've seen it.
>> And if you're a video gamer platforms like Steam, they have a Ubuntu
installer image whereas installing it on Red Hat is borderline impossible.
So, from a amateur home user side a Ubuntu to is a lot more friendly, but
from a workplace side CentOS and RHEL are really kinda the way to go.
And oftentimes companies will mix the two using CentOS where
scalability is necessary and they're not gonna need support.
And using RHEL where stability is important, and they may need support.
>> All right, so RHEL it cost money,
there's support, lots of good things that come with it as well.
And then CentOS it's free, good for if you're learning Linux in an enterprise
environment, maybe that way you can go back to Red Hat.
Thank you so much Don.
Is there anything I'm missing?
>> No, that's pretty good summary and just remember,
CentOS is an amazing product in and of itself.
Amazon Linux if you go and deploy an Amazon,
they call it the Amazon Linux AMI that you deploy in AWS, just so
many acronyms, but it is all built off of CentOS.
So if it's good enough for them,
it's pretty much good enough for everybody else on the planet.
So don't feel bad at picking one over the other but
they each really do have their specific use case.
>> All right, this has been RHEL and CentOS.
Thank you so much Don, for guiding us through that.
And thank you all there for watching, signing off for ITProTV.
I've been your host, Audrey Spurgeon.
>> And I'm Don Pezet.
>> And we'll see you next time.
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>> Thank you for watching ITProTV.