RHEL or CentOS?

Cheatah

Should companies like hosting providers use RHEL or CentOS on their production machines?

Red Hat Enterprise Linux comes with official support from Red Hat, Inc. based on a SLA. But many companies have their own technical personnel and rarely require 3rd party support.

Should such companies use RHEL even though CentOS is built upon almost exactly the same code? Or should their customers choose? Large customers? Business-critical solutions? Governmental agencies?

My company mainains hundreds of servers, many running CentOS (migrated from FreeBSD), a few running Debian, but no servers actually running RHEL.

Under what circumstances should companies choose for Red Hat Enterprise Linux or CentOS?

jnvilo

We use RHEL only on oracle databases primarily because we need the oracle support and oracle will simply drop the phone when they hear that you are not running on a certified OS.

But for everything else, I install Centos. If the software/developers tell me RHEL, I go back to them explaning that Centos is exactly RHEL without the Redhat support that I won't need/use anyway.

quaid

Sometimes it comes down to simply how you feel about the control of your own future.

Working directly with Red Hat puts you in an important position, a paying customer, with the people who are experts at getting problems fixed and new features included in upstream projects.

Red Hat is the catalyst between you as a customer and many thousands of upstreams, not just the Linux kernel. Take a look at some of the past and ongoing contributions that have come from Red Hat, some of which were influenced by customer requests:

http://fedoraproject.org/wiki/Red_Hat_contributions

When you use a rebuild of Enterprise Linux, you gain the same benefits flowing downstream that Red Hat customers gain, but you change the dynamics of how you can manage your relationship with the upstream.

Is your in-house support staff prepared to negotiate with upstream projects on your behalf? Work to get patches and features included in the code?

If they are, that is great; the world needs more corporations that are contributing from within their own IT staff. Again, though, when doing that, having a partner, such as Red Hat, to work with on negotiating through the upstream maze can be helpful.

People who work to produce Enterprise Linux rebuilds are in the same position with regard to how they can influence the upstream. If they are a paying customer, they can ask Red Hat for help. If not, they are welcome with everyone else to participate in the upstream project for RHEL, which also considers itself the upstream for CentOS, Scientific Linux, Whitebox Linux, and the myriad other rebuilds:

http://join.fedoraproject.org

For a long view on how and why this works, I encourage you to take 9 mins and 21 seconds to watch Michael Tiemann talk about "The Open Source Triple Play":

http://www.youtube.com/watch?v=ntzp8z14OXQ

http://www.redhat.com/magazine/001nov04/features/tripleplay/

zillion

I agree with Karsten Wade . However even if the inhouse staff is competent enough to push in features for the upstream, when it comes to getting those features backported to RHEL, you will have to be a RHEL customer. Also the flip side of using CentOS is patching the system with critical security erratas which come in Centos only after a RHEL minor release ( like RHEL5.1 , RHEL5.2 ) and for which you might have to wait for like 6 months. Same is the case with critical bug fixes for which you can get hotfixes if you are using RHEL. For all mission critical applications I would strongly recommend RHEL .

atreyu

Cheatah wrote:

Should companies like hosting providers use RHEL or CentOS on their production machines?

Red Hat Enterprise Linux comes with official support from Red Hat, Inc. based on a SLA. But many companies have their own technical personnel and rarely require 3rd party support.

Should such companies use RHEL even though CentOS is built upon almost exactly the same code? Or should their customers choose? Large customers? Business-critical solutions? Governmental agencies?

My company mainains hundreds of servers, many running CentOS (migrated from FreeBSD), a few running Debian, but no servers actually running RHEL.

Under what circumstances should companies choose for Red Hat Enterprise Linux or CentOS?

I never use CentOS, if the requirement is to fully support it, 24/7, with <1% downtime. Very likely, I could fix any probs myself. But if not, it would mean my a$$. However, in reality, I use CentOS all the time, whenever possible, b/c it is easier to reinstall it, update it, and use get additional software for it. And I don't support a Ginormous Corporation of end-users. or NORAD.

Sometimes the customer has strict requirements about the accreditation of the software (USG) and you're stuck with RHEL, or even RHEL+SELINUX <shudder>.

I would add that I've never run across a CentOS problem/bug that was not also a RHEL problem/bug.

quaid

However, in reality, I use CentOS all the time, whenever possible, b/c it is easier to reinstall it, update it, and use get additional software for it. And I don't support a Ginormous Corporation of end-users. or NORAD.

Have you ever expressed those reasons for using CentOS back to anyone at Red Hat, formally? Such as a support person, sales person, or sales engineer?

I ask because I find many people who are not CentOS users think folks use it because it is no-cost to them. In fact, when you talk with people, the no-cost is only one of the reasons.

If, when in a customer role, you tell Red Hat about the parts of CentOS that you prefer, and/or why you don't use RHEL in all those places, you may help influence Red Hat positively.

Regarding getting additional software, I presume you use the Extra Packages for Enterprise Linux (EPEL) repository?

http://fedoraproject.org/wiki/EPEL

The repos for EL4 and EL5 are full of thousands of community-supported packages of software that did not ship with the associated RHEL version. In some cases, RHEL updates have pulled packages from EPEL inclusion in the update. Very cool.

deploylinux

I have considered CentOS several times in the past as RHEL licenses cost quite a bit of $ each year and cost cutting has been the "in" thing business wise ever since the dotcom bust.

Still, we stick with paying RedHat for RHEL licenses each year, because:

a) Most of our deployments are on VMware ESX whose release notes on the Linux side are constantly focused on RHEL. Debugging issues can get very complicated in a private cloud, and we just can't afford the added confusion that might occur if we contacted VMware/Dell/Random Application Vendor and told them we were using CentOS rather than RedHat.

b) I've been disappointed many times in seeing very long wait times between when Redhat releases a patch/upgrade and when CentOS finally gets around to repackaging it. When a critical security patch is released, even an hour or two can be important for deployment.

c) While I honestly would prefer that my primary distribution be community based, I would expect the community to be innovating/etc. I'm not sure how I feel about centos basically just being a clone of redhat. Free is nice, but I feel better compensating RedHat for the value it provides.

d) Telephone/Email support from RedHat isn't really a factor. In the last 10 years, I might have had to open a ticket perhaps 3 times. Most other issues were handled without even going to the redhat website, although sometimes it is helpful to read or update bugzilla.

atreyu

quaid wrote:

However, in reality, I use CentOS all the time, whenever possible, b/c it is easier to reinstall it, update it, and use get additional software for it. And I don't support a Ginormous Corporation of end-users. or NORAD.

Have you ever expressed those reasons for using CentOS back to anyone at Red Hat, formally? Such as a support person, sales person, or sales engineer?

I ask because I find many people who are not CentOS users think folks use it because it is no-cost to them. In fact, when you talk with people, the no-cost is only one of the reasons.

If, when in a customer role, you tell Red Hat about the parts of CentOS that you prefer, and/or why you don't use RHEL in all those places, you may help influence Red Hat positively.

Regarding getting additional software, I presume you use the Extra Packages for Enterprise Linux (EPEL) repository?

http://fedoraproject.org/wiki/EPEL

The repos for EL4 and EL5 are full of thousands of community-supported packages of software that did not ship with the associated RHEL version. In some cases, RHEL updates have pulled packages from EPEL inclusion in the update. Very cool.

No, I haven't communicated my opinions with Red Hat. To be honest, the one single time I had a reason to interface with them, it was pretty unimpressive (on their part, I was spectacular, of course). But, yes, the squeaky wheel gets the grease...

I have actually missed the boat on EPEL until just earlier today (somebody mentioned it on another fine post at LINUX.COM). But I should have been more clear about what I mean about getting software. Often, I have a box that I'm supporting and I need a source or binary RPM. well, it is easy to get it off the net if it is CentOS. not so easy for RHEL, if i don't have the CD/DVD handy. or if i don't have a RHN login (which I often don't, b/c someone else has it and doesn't want to give it out and is out sick that day, etc.).

Also, I could swear that the CentOS distro itself comes with more packages that the RHEL equivalent, but I could be wrong on that point.

woboyle

I use CentOS for my business. The fact of the matter is that Red Hat will sell support contracts for CentOS now on the same terms they sell support contracts for RHEL. Any software company that supports RHEL distributions, should NOT, in my opinion, be allowed to deny support for CentOS users.

Tarek Ahmed

I think the only difference is the paid support.

quaid

I use CentOS for my business. The fact of the matter is that Red Hat will sell support contracts for CentOS now on the same terms they sell support contracts for RHEL.

That's interesting, do you have a pointer/URL to that information?

Any software company that supports RHEL distributions, should NOT, in my opinion, be allowed to deny support for CentOS users.

Functionally, the software is the same, when it comes to you and I administering servers. But they are different binary packages. Red Hat has binary packages that are tested against hardware and software (hundreds? of vendors), and that is what is certified.

When doing a rebuild of the SRPMS, an Enterprise Linux rebuilt distro team could make changes when building the binary packages. That introduces doubt in a troubleshooting process. It makes it harder for a third-party vendor and a customer working through an IT issue.

It's not the fear of the unknown but rather the comfort with the known that is at the heart of why one cares about the source and process of binary RPMs.

It is that added complexity that makes it hard for a vendor to support non-Red Hat binary RPMs.

Another way to think of this is, if it were easy and desirable to support Enterprise Linux rebuilds, wouldn't there be multiple companies doing that on a large scale?

quaid

I think the only difference is the paid support.

Well, it's a bit more than that.

[ul]
[li]The binary RPMs from Red Hat are the ones that hundreds of hardware and software vendors certify against. That is an important difference when you are troubleshooting.[/li]
[li]The control of the RHEL roadmap is in Red Hat's hands. There are only a few ways to influence that roadmap. You can work in Fedora, as many CentOS people do, or in other upstream projects directly, and let that trickle down to the next RHEL release. Or you can be a customer and have your product managers work on it for you.[/li]
[li]When it comes to working with upstreams on the behalf of customers, Red Hat has the longest and greatest record in this industry. If you are prepared to work on your own behalf in any upstreams that matter to your business, then you have one way to keep control of your future. Another is to have Red Hat do it for you.[/li]
[/ul]

Interesting that the question of "RHEL or CentOS?" is often discussed on both sides as a matter of cost. When you look at it further, you find there are legitimate reasons to decide either way, depending on your needs and resources.

sbennett

It comes down to the requirements of your organization/company. If you have a support (i.e.SLA) requirement, then you would be wise to use RHEL. However, CentOS can suffice for any needs that come from the use of RHEL. You would have to decide on the requirements of your company/organization.

If you do have a hiccup <which will eventually happen> you need to make dang sure that you have a plan to CYA if you are not using RHEL.

woboyle

If you are familiar with the CentOS / Red Hat relationship, you probably wouldn't say so much. It is not just built from the SRPMS. FYI, CentOS is widely used in the financial industry for the servers that run many co-located trading platforms used by the market makers at the NYSE, NASDAQ, CBOE, and other major exchanges world wide. These are systems where high reliability is essential since a few seconds of downtime for algorithmic derivatives trading can run up loses of million$. A company I used to work for developing risk analysis software develops, manages, and sells as a service the quoting/trading/hedging software used by most of the market makers and professional options traders at the CBOE. They migrated all their servers to CentOS last year.

quaid

woboyle wrote:

If you are familiar with the CentOS / Red Hat relationship, you probably wouldn't say so much. It is not just built from the SRPMS.

Can you clarify what you mean by these statements?

FYI, CentOS is widely used in the financial industry for the servers that run many co-located trading platforms used by the market makers at the NYSE, NASDAQ, CBOE, and other major exchanges world wide.

Yep, I'm sure it is, as is RHEL itself. I recall when NYSE switched to RHEL:

http://searchenterpriselinux.techtarget.com/news/article/0,289142,sid39_gci1316018,00.html

These are systems where high reliability is essential since a few seconds of downtime for algorithmic derivatives trading can run up loses of million$. A company I used to work for developing risk analysis software develops, manages, and sells as a service the quoting/trading/hedging software used by most of the market makers and professional options traders at the CBOE. They migrated all their servers to CentOS last year.

Actually, I'm a bit surprised at this. Considering that the RHEL technologies seem to be at the core of that business, why would they move themselves farther downstream?

Perhaps they are embedding their own developers directly in the upstreams that matter to them? Or they don't understand what open source truly is about and why it is better software?

My experience is that the financial services companies are interested in supported software, and some of them also understand the open source model intimately. For example, JP Morgan decided to open their code to gain the advantage of an open source collaboration and an open standard (http://www.infoq.com/news/2008/08/amqp-progress). The resulting open standards working group (http://amqp.org) was formed by AMQP's originator, John O’Hara, and when he wanted that group and mission to grow, he got Red Hat involved. From the reference implementation (http://qpid.apache.org) to Red Hat MRG (http://www.redhat.com/mrg/), Red Hat been involved in making this open source project successful.

Could John O'Hara have turned to the CentOS community for that work? Perhaps. Instead, I suspect that community would have told John to talk with Red Hat.

d0glesby

The three reasons to run RHEL (from my experience):

1.> You have third-party software that requires RHEL for support purposes.

2.> You have hardware that is exotic, and requires cooperation between RedHat and the hardware vendor to make things work, or fix problems down the road.

3.> You would rather manage machines instead of actively administrate them (for whatever reason).

I have worked for an organization that had to use RHEL for any one or combination of those three reasons. We also used CentOS on all development machines (much more Linux friendly than some of the production hardware we used), and for our own in-house servers.

woboyle

You can purchase support contracts from Red Hat for CentOS now. Also, I know a number of major software vendors in the financial trading markets (stock and options exchanges) that run CentOS on their trading/quoting servers that are co-located at the exchanges, such as NYSE, CBOE, etc. Personally, I think the choice is 6 of 1 and a half dozen of the other. So, a lot of the decision is going to be related to executive "comfort level".

quaid

woboyle wrote:

You can purchase support contracts from Red Hat for CentOS now.

This is the second time in this thread you have asserted this. Can you provide some supporting information? URL?

I'm certain that Red Hat is not selling support subscriptions for CentOS systems. The whole idea of support and services for RHEL is that they are the certified binaries built on Red Hat infrastructure. The CentOS binaries are rebuilt, they are not the same as the Red Hat binaries.

Also, I know a number of major software vendors in the financial trading markets (stock and options exchanges) that run CentOS on their trading/quoting servers that are co-located at the exchanges, such as NYSE, CBOE, etc. Personally, I think the choice is 6 of 1 and a half dozen of the other. So, a lot of the decision is going to be related to executive "comfort level".

This also you asserted before without supporting information, and I replied there as well.

If those businesses want to move themselves farther downstream from being able to affect the direction of the technology they rely upon, that is up to them. I sure hope they know what they are doing, and I mean much, much beyond, "Can your Linux admins support this system without calling Red Hat?"

But it is hardly equivalent (6 of 1, 1/2 dozen). Anyone who recommends what you get from Red Hat and what you get from the CentOS community as equivalent is giving bad advice. I'm positive the CentOS community agrees -- they often tell people who want 24x7 instant support to stop hammering the community and go get a subscription from Red Hat.

gavin2u

I have using CentOS instead of RHEL for 2 years.

Free, OR DIE. :P

woboyle

I am in the process of verifying my statement with Red Hat regarding support for CentOS deployments and will post again when I hear from them.

quaid

gavin2u wrote:

I have using CentOS instead of RHEL for 2 years.

Free, OR DIE. :P

Hee hee, never met anyone who was wiling to die for no-cost. ;-P

woboyle

Speak for yourself gavin2u... Let's put it another way - I'd kill before I was forced to run Windows on my workstation, other than in a locked-down VM! >

Goineasy9

@gavin2u
There are many here that feel that strongly. Look up RMS on You Tube and watch him in action.
I'll leave it that, off topic for this thread.

scottco229

for what it is worth, I will speak as an end user of linux, I use Centos, and have never used RHEL. Primarily because in looking for the type of Linux I want to run, I have changed multiple times from Fedora, Open Suze, Centos, LinxMint, and I like the freedom of changing with out costing anything. This being stated I have contrinuted donated funds for the use of Centos.

I have returned to Centos because it does install on my dell 1501, and I can easily configure my wireless card, and it works with the video card installed. Non of the others will work, I can't even get to command line, I get a gray streaked screen.

I do however think that supporting RHEL is important because of what it means overall to the Linux community. I dont have a windows run computer in my house, I have 4 computers running different versions of Linux and 1 Mac for my kids..who will be running linux next year.