Started my new job today and I have to learn Red Hat Enterprise

zen master

darkerosxx wrote: »

I'm not telling you not to use CentOS, just that if you're going to use RHEL on the job, you'd be best served by using RHEL to learn.

I agree completely. No point using something that's "easier" when you'll have to use the harder version on the job. Go with RHEL, and figure out how to deal with all its weird quirks.

Forsaken_GA

Absolutely nothing, save for the way yum operates.

The CentOS crew takes the RHEL source, strips the Red Hat branding, adds their own, and then recompiles it. RHEL by default cripples yum, it won't update anything until you register it. CentOS's yum will work out of the box.

veritas_libertas

JDMurray wrote: »

I've always heard that CentOS was a free release of Red Hat created in reaction to the for-pay release of Red Hat Enterprise. I've also heard that CentOS is more secure out-of-the-box than RHE. I know several security-minded businesses that won't use anything else but CentOS for their servers.

This is a very interesting topic. I have heard little about CentOS except on TE.

Forsaken_GA

darkerosxx wrote: »

Dear wal-mart,

I know you asked me to grow bananas, but I like plantains because they're pretty much the same thing. They look and taste almost exactly like bananas! You should definitely honor your contract to buy bananas, even though I'm offering you plantains!


(Is that similar to what you're saying? Since he was told he'd be working on RHEL, NOT CENTOS, that's how I see your argument, so tell me if I'm wrong.)

Ok, you're wrong.

The difference between CentOS and RHEL is not the same as the difference between bananna's and plantains. It's the difference between the box of cereal labelled Rice Chex and the box of cereal labelled Great Value Toasted Rice Cereal (or whatever your store's generic is, I'm keeping with the Wal-Mart theme). Wal-mart doesn't do their own manufacturing, they just relabel and distribute the same product.

Try actually working with both pieces of software before commenting on them in the future, please. These forums are supposed to be about sharing information, not the spread of disinformation.

Again, I'm not trying to be a dick, I'm not trying to flame, or force my opinion down anyone's throat. All I'm doing is providing counterpoint and encouraging you to check your facts, because you've made some assumptions which are not correct, and committing the cardinal sin (in my world anyway) of attempting to represent your opinion as fact.

dynamik

The analogies in this thread are awesome

Turgon

JDMurray wrote: »

I've always heard that CentOS was a free release of Red Hat created in reaction to the for-pay release of Red Hat Enterprise. I've also heard that CentOS is more secure out-of-the-box than RHE. I know several security-minded businesses that won't use anything else but CentOS for their servers.

Cant comment, except to say I was once told by an Open BSD hippie that RedHat was easily rooted and all kinds of toot you had to strip out when installing. He preferred Open BSD no drool.

From what Forsaken is saying CentOS and RHE are basically the same. Are they therefore just as secure/insecure?

JDMurray

OpenBSD is a UNIX kernel and RHE/CentOS is a Linux kernel, so they are apple-n-oranges for comparison.

I'd guess that from a design and implementation perspective, CentOS and RHE are nearly identical security-wise, but their default configurations probably differ enough to make one more secure (by default) than the other. I've always heard "CentOS" and "very secure OS" in the same sentence.

Turgon

JDMurray wrote: »

OpenBSD is a UNIX kernel and RHE/CentOS is a Linux kernel, so they are apple-n-oranges for comparison.

I'd guess that from a design and implementation perspective, CentOS and RHE are nearly identical security-wise, but their default configurations probably differ enough to make one more secure (by default) than the other. I've always heard "CentOS" and "very secure OS" in the same sentence.

Well there we are then. Yes he prefered OpenBSD over RH any day. Not a linux fan from a drool or security perspective if I recall.

seuss_ssues

You sir are correct. That is all.

Forsaken_GA wrote: »

Ok, you're wrong.

The difference between CentOS and RHEL is not the same as the difference between bananna's and plantains. It's the difference between the box of cereal labelled Rice Chex and the box of cereal labelled Great Value Toasted Rice Cereal (or whatever your store's generic is, I'm keeping with the Wal-Mart theme). Wal-mart doesn't do their own manufacturing, they just relabel and distribute the same product.

Try actually working with both pieces of software before commenting on them in the future, please. These forums are supposed to be about sharing information, not the spread of disinformation.

Again, I'm not trying to be a dick, I'm not trying to flame, or force my opinion down anyone's throat. All I'm doing is providing counterpoint and encouraging you to check your facts, because you've made some assumptions which are not correct, and committing the cardinal sin (in my world anyway) of attempting to represent your opinion as fact.

Forsaken_GA

JDMurray wrote: »

OpenBSD is a UNIX kernel and RHE/CentOS is a Linux kernel, so they are apple-n-oranges for comparison.

I'd guess that from a design and implementation perspective, CentOS and RHE are nearly identical security-wise, but their default configurations probably differ enough to make one more secure (by default) than the other. I've always heard "CentOS" and "very secure OS" in the same sentence.

To address both your and Turgon's points, these are pretty much just issues of OS partisan-ship. OpenBSD fans are going to think *everything* else is a piece of crap when it comes to security, because security is the end-all be-all of OpenBSD culture.

In terms of CentOS/RHEL security, I've never noticed a big difference. Both of them want to turn on SELinux and iptables during the install, but no one in their right mind trusts the stock settings of any install (not without verifying it afterwards to make sure it's what they want).

I personally think anything RH produces is a piece of utter crap (and Centos is guilty as well by extension) and the only use I have for either of them is as an LDAP server, since Debian and it's derivatives leave much to be desired when it comes to OpenLDAP. However, I recognize that these are my personal prejudices, and I never pushed them off on a customer. Everyone has their preferred environment, and if the customers developers wanted to work with RHEL or CentOS, that's what they got, and we learned how to manage it.

Forsaken_GA

Turgon wrote: »

Well there we are then. Yes he prefered OpenBSD over RH any day. Not a linux fan from a drool or security perspective if I recall.

I do as well, to be honest, and for the same reasons I like Debian. The OpenBSD footprint is very small. The base install is pretty much your absolutely necessary userland commandline tools, OpenSSH, and apache. That's it. You want more, you have to install it. This makes management of a machine much easier, as the signal to noise ratio of installed software is alot better.

RHEL/CentOS likes to install a bunch of unnecessary crap by default. Especially if you let it install the GUI interface. You can short circuit this during install, and it's not particularly difficult, even if it is time consuming, but you can achieve the same minimal install, which you can then add to as you go along. (Debian can also be guilty of this, as if you choose any of the 'pre-packaged' environments during install, you're going to get some bloat, but it's typically not as bad as RH and it's derivatives)

Fedora is the absolute king of installing useless crap. I would rather use Windows than be forced to use a Fedora box.

Turgon

Forsaken_GA wrote: »

I do as well, to be honest, and for the same reasons I like Debian. The OpenBSD footprint is very small. The base install is pretty much your absolutely necessary userland commandline tools, OpenSSH, and apache. That's it. You want more, you have to install it. This makes management of a machine much easier, as the signal to noise ratio of installed software is alot better.

RHEL/CentOS likes to install a bunch of unnecessary crap by default. Especially if you let it install the GUI interface. You can short circuit this during install, and it's not particularly difficult, even if it is time consuming, but you can achieve the same minimal install, which you can then add to as you go along. (Debian can also be guilty of this, as if you choose any of the 'pre-packaged' environments during install, you're going to get some bloat, but it's typically not as bad as RH and it's derivatives)

Fedora is the absolute king of installing useless crap. I would rather use Windows than be forced to use a Fedora box.

There we are then. So if security is a worry consider OpenBSD. We used it as a firewall running PF.

tpatt100

Come to find out if I need books the company will order them for me just have to put in a request at HR. I just have to keep it at work, not a problem for me really let's me study there rather than at home.

I have to research an information classification model/method now. Guess they had an older method in place and want me to implement a more recent model. I am really grateful I can learn all this stuff at my own pace.

Guess once you have a job is when you get other calls also. GE built a new facility here in Michigan. I applied just for the hell of it. Once I started my new job , GE called me three times this past week wanting to meet with me for an Access Control engineer position. I told them no since I just accepted one but then I had this nagging feeling all day that I should have went just to see what they had. They are hiring over a hundred engineers for different positions now at this facility.

impelse

Always is the same, when you get a job everybody begin to call you.

darkerosxx

Forsaken_GA wrote: »

Ok, you're wrong.

The difference between CentOS and RHEL is not the same as the difference between bananna's and plantains. It's the difference between the box of cereal labelled Rice Chex and the box of cereal labelled Great Value Toasted Rice Cereal (or whatever your store's generic is, I'm keeping with the Wal-Mart theme). Wal-mart doesn't do their own manufacturing, they just relabel and distribute the same product.

Try actually working with both pieces of software before commenting on them in the future, please. These forums are supposed to be about sharing information, not the spread of disinformation.

Again, I'm not trying to be a dick, I'm not trying to flame, or force my opinion down anyone's throat. All I'm doing is providing counterpoint and encouraging you to check your facts, because you've made some assumptions which are not correct, and committing the cardinal sin (in my world anyway) of attempting to represent your opinion as fact.

Take your own words and eat them, then. RHEL has no "crippled" yum. It works exactly as intended... with their servers... the same way CentOS does. The only difference is their servers require a license to access them. Create your own repo server, boom, done. I already admitted it would be easier for him to use CentOS if his business doesn't have repo servers set up or a license for him to use.

The guy is going to be working with RHEL in the workplace. How is he best served by using anything other than RHEL to study, given the above exception that he has access to packages?

Edit to add: By the way, I do still think it's plantain/bananas. Your analogy works, too though. Different trees, different vendors. It looks and tastes different and there will be some structural differences. They are not one in the same. Because of this, if you go to buy a banana, you're likely not going to walk out with a plantain. If you go to buy a box of Chex, you're likely not going to walk out with a box of great value imitation. If you're told you'll be using RHEL at work... fill that in with whatever you want and let's end it here, cause we've taken up enough of this guy's thread.

darkerosxx

tpatt100 wrote: »

Come to find out if I need books the company will order them for me just have to put in a request at HR. I just have to keep it at work, not a problem for me really let's me study there rather than at home.

I have to research an information classification model/method now. Guess they had an older method in place and want me to implement a more recent model. I am really grateful I can learn all this stuff at my own pace.

Guess once you have a job is when you get other calls also. GE built a new facility here in Michigan. I applied just for the hell of it. Once I started my new job , GE called me three times this past week wanting to meet with me for an Access Control engineer position. I told them no since I just accepted one but then I had this nagging feeling all day that I should have went just to see what they had. They are hiring over a hundred engineers for different positions now at this facility.

That's cool! Hey, you may want to call them back and just go in to see if they're paying more than your current job.

tpatt100

darkerosxx wrote: »

That's cool! Hey, you may want to call them back and just go in to see if they're paying more than your current job.

I thought about it but then decided against it. Main reason being is there is a lot of stuff I forgot and I need refreshing on and this job will allow it without all the stress of jumping through hoops trying to learn on the fly. I was pretty much given the option to decide what security direction I want to go in and I doubt I can do that anywhere else.

darkerosxx

Great reasons and perfectly understandable. Remember, if you ever need any help with stuff for Linux, we have the Linux forum way down the line. I linked it earlier.

Forsaken_GA

darkerosxx wrote: »

Take your own words and eat them, then. RHEL has no "crippled" yum. It works exactly as intended... with their servers... the same way CentOS does. The only difference is their servers require a license to access them. Create your own repo server, boom, done. I already admitted it would be easier for him to use CentOS if his business doesn't have repo servers set up or a license for him to use.

The guy is going to be working with RHEL in the workplace. How is he best served by using anything other than RHEL to study, given the above exception that he has access to packages?

Edit to add: By the way, I do still think it's plantain/bananas. Your analogy works, too though. Different trees, different vendors. It looks and tastes different and there will be some structural differences. They are not one in the same. Because of this, if you go to buy a banana, you're likely not going to walk out with a plantain. If you go to buy a box of Chex, you're likely not going to walk out with a box of great value imitation. If you're told you'll be using RHEL at work... fill that in with whatever you want and let's end it here, cause we've taken up enough of this guy's thread.

Alright, now you're just being stubborn.

Meh, I've made my point. You're entitled to your opinion.

dynamik

Is anyone going to address what the difference between the two is? I thought it was just branding and support. I don't see why this matters, so I'm curious about the actual differences.

Forsaken_GA

I guess I didn't make my point hehe

They are, for all intents and purposes, the same thing. One's just branded differently, costs money, and has the support of the company behind it. The other, for support, you're at the mercy of your staff, the projects communication channels, and Google.

You can copy a binary from a RHEL system to a Centos system (and vice versa) and it will work without issue. They can use each others RPM's without issue (assuming same version... if you copy a RHEL4 binary to a Centos5.3 system, there are probably going to be some issues because they're probably linked to different library versions. Common sense *does* apply)

The entire reason CentOS got started was because Red Hat decided they wanted to make some money off their work, which is not unreasonable. But the Linux world likes free software. Thanks to the GPL, Red Hat has to make the source code available. They cannot prevent someone else from downloading the source, recompiling it, and redistributing it. They can, however, enforce their trademark, which is what they did. This forces the rebranding and that's why we have CentOS. It's not like the difference between Debian and Ubuntu (because the Ubuntu guys tweak the hell out of the Debian testing repo's, and they're also not as militant on license enforcement.... there's a reason why Ubuntu has Firefox and Debian has Iceweasel). CentOS is for the folks who used to use Red Hat Linux for free, and wanted to keep on using it's natural progression when it became Red Hat Enterprise Linux. I think my disdain for RHEL stems from the fact that it comes from a Fedora base (though the two are DRASTICALLY different now), and I absolutely hate Fedora.

Now, with all that said - CentOS *does* have developers, and it can be different than RHEL. There are repo's available for CentOS specific stuff. (The CentOS guys also tend to contribute their changes back upstream. Red Hat isn't particularly fond of CentOS, since they cause a revenue loss, but they have gotten some code out of it). This is something the admin has to do on purpose though. The mandate for each major release of CentOS is 100% binary compatibility with the equivalent RHEL version

Bl8ckr0uter

Forsaken_GA wrote: »

I guess I didn't make my point hehe

They are, for all intents and purposes, the same thing. One's just branded differently, costs money, and has the support of the company behind it. The other, for support, you're at the mercy of your staff, the projects communication channels, and Google.

You can copy a binary from a RHEL system to a Centos system (and vice versa) and it will work without issue. They can use each others RPM's without issue (assuming same version... if you copy a RHEL4 binary to a Centos5.3 system, there are probably going to be some issues because they're probably linked to different library versions. Common sense *does* apply)

The entire reason CentOS got started was because Red Hat decided they wanted to make some money off their work, which is not unreasonable. But the Linux world likes free software. Thanks to the GPL, Red Hat has to make the source code available. They cannot prevent someone else from downloading the source, recompiling it, and redistributing it. They can, however, enforce their trademark, which is what they did. This forces the rebranding and that's why we have CentOS. It's not like the difference between Debian and Ubuntu (because the Ubuntu guys tweak the hell out of the Debian testing repo's, and they're also not as militant on license enforcement.... there's a reason why Ubuntu has Firefox and Debian has Iceweasel). CentOS is for the folks who used to use Red Hat Linux for free, and wanted to keep on using it's natural progression when it became Red Hat Enterprise Linux. I think my disdain for RHEL stems from the fact that it comes from a Fedora base (though the two are DRASTICALLY different now), and I absolutely hate Fedora.

Now, with all that said - CentOS *does* have developers, and it can be different than RHEL. There are repo's available for CentOS specific stuff. (The CentOS guys also tend to contribute their changes back upstream. Red Hat isn't particularly fond of CentOS, since they cause a revenue loss, but they have gotten some code out of it). This is something the admin has to do on purpose though. The mandate for each major release of CentOS is 100% binary compatibility with the equivalent RHEL version

Ok so for someone who is new to the linux world and is already working with Ubuntu and Ubuntu Server, would CentOS be "RH enough" to get through the RHCT/E certs (assuming proper amounts of studying and time is spent, and materials are use)? Or put a Different way could a person go through a Micheal Jang book and use CentOS and be ok?

EDIT: The reason why I am asking is that I have seen many books on RH and a few on CENTOS, and still a few others on RH/FEDORA but none on RH/CENTOS. Which leads me to believe that there are some significant differences, no?

EDIT EDIT: I am not trying to argue, I am just generally curious?

L0gicB0mb508

knwminus wrote: »

Ok so for someone who is new to the linux world and is already working with Ubuntu and Ubuntu Server, would CentOS be "RH enough" to get through the RHCT/E certs (assuming proper amounts of studying and time is spent, and materials are use)? Or put a Different way could a person go through a Micheal Jang book and use CentOS and be ok?

EDIT: The reason why I am asking is that I have seen many books on RH and a few on CENTOS, and still a few others on RH/FEDORA but none on RH/CENTOS. Which leads me to believe that there are some significant differences, no?

EDIT EDIT: I am not trying to argue, I am just generally curious?

In my Linux course for the RHCE we used CentOS. There is no difference under the hood from RHEL to CentOS. If you are good with CentOS, you'll be good with RHEL. In a server environment you wont be using a GUI much anyway. CLI is going to be nearly identical on both operating systems.

From the CentOS site:
"CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor. CentOS conforms fully with the upstream vendors redistribution policy and aims to be 100% binary compatible. (CentOS mainly changes packages to remove upstream vendor branding and artwork.) CentOS is free."

Bl8ckr0uter

L0gicB0mb508 wrote: »

In my Linux course for the RHCE we used CentOS. There is no difference under the hood from RHEL to CentOS. If you are good with CentOS, you'll be good with RHEL. In a server environment you wont be using a GUI much anyway. CLI is going to be nearly identical on both operating systems.

From the CentOS site:
"CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor. CentOS conforms fully with the upstream vendors redistribution policy and aims to be 100% binary compatible. (CentOS mainly changes packages to remove upstream vendor branding and artwork.) CentOS is free."

Cool. I think I found a new project.

yuriz43

Forsaken_GA wrote: »

I guess I didn't make my point hehe

They are, for all intents and purposes, the same thing. One's just branded differently, costs money, and has the support of the company behind it. The other, for support, you're at the mercy of your staff, the projects communication channels, and Google.

You can copy a binary from a RHEL system to a Centos system (and vice versa) and it will work without issue. They can use each others RPM's without issue (assuming same version... if you copy a RHEL4 binary to a Centos5.3 system, there are probably going to be some issues because they're probably linked to different library versions. Common sense *does* apply)

The entire reason CentOS got started was because Red Hat decided they wanted to make some money off their work, which is not unreasonable. But the Linux world likes free software. Thanks to the GPL, Red Hat has to make the source code available. They cannot prevent someone else from downloading the source, recompiling it, and redistributing it. They can, however, enforce their trademark, which is what they did. This forces the rebranding and that's why we have CentOS. It's not like the difference between Debian and Ubuntu (because the Ubuntu guys tweak the hell out of the Debian testing repo's, and they're also not as militant on license enforcement.... there's a reason why Ubuntu has Firefox and Debian has Iceweasel). CentOS is for the folks who used to use Red Hat Linux for free, and wanted to keep on using it's natural progression when it became Red Hat Enterprise Linux. I think my disdain for RHEL stems from the fact that it comes from a Fedora base (though the two are DRASTICALLY different now), and I absolutely hate Fedora.

Now, with all that said - CentOS *does* have developers, and it can be different than RHEL. There are repo's available for CentOS specific stuff. (The CentOS guys also tend to contribute their changes back upstream. Red Hat isn't particularly fond of CentOS, since they cause a revenue loss, but they have gotten some code out of it). This is something the admin has to do on purpose though. The mandate for each major release of CentOS is 100% binary compatibility with the equivalent RHEL version

Forsaken, you are absolutely correct on every single point. I really do not see why someone would argue this.

Centos and Redhat are at their essence, exactly the same. If you've learned one, you've learned the other. I'm speaking purely in the view of a Sys Admin. They have the same configuration file layout in /etc, same style of rc scripts, same package management system, and the same unique system utilities.

Forsaken_GA

knwminus wrote: »

Ok so for someone who is new to the linux world and is already working with Ubuntu and Ubuntu Server, would CentOS be "RH enough" to get through the RHCT/E certs (assuming proper amounts of studying and time is spent, and materials are use)? Or put a Different way could a person go through a Micheal Jang book and use CentOS and be ok?

EDIT: The reason why I am asking is that I have seen many books on RH and a few on CENTOS, and still a few others on RH/FEDORA but none on RH/CENTOS. Which leads me to believe that there are some significant differences, no?

EDIT EDIT: I am not trying to argue, I am just generally curious?

Yes, you can study for the red hat certs with centos. Which is exactly what I would use if I ever do decide to take the RHCE (I moved from system administration to network engineering, and we use primarily debian anyway, so I have no good work reason to take it. If the price tag were *much* lower, I'd probably take it anyway, but the price is a bit high for a "just for the hell of it" cert, especially since recertification means retaking the entire thing all over again).

A big part of the reason as to why there's so little CentOS literature is because there's simply no need. What applies to RHEL, applies to CentOS.

phoeneous

Ive found these useful with the little Linux that Ive had to do at work. Congrats on the job btw, I would kill to be in security. Enjoy the hours!

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