CentOS vs RHEL – Are They Exactly the Same?

centosrhel

I'm sure this question has been asked again and again elsewhere (I did not find anything specific to CentOS vs RHEL in SE), but I would still like to ask and confirm a few specific points.

I am well aware that CentOS removes all RH trademarks, logos, etc. and is based on the same codes with packages built by the community.

  • Are the packages built for CentOS exactly the same? Will the contents of the packages and the behavior of the programs be identical to those found on RHEL?
  • What is RHN other than a medium for license registration? What is it to CentOS?

I'm an Ubuntu desktop user. Attended a RH299 course which did not really touch anything about the support aspect (i.e. RHN). Other than that I've no professional Linux knowledge or experience.

EDIT

I did read the CentOS 6.2 release notes, but I found the details unsatisfactory. The release notes mentions packages modified, removed or added to upstream. But it neither explains nor links to any document detailing what exactly is different in the modified packages. Granted the branding packages are self-explanatory, but it mentions packages like kernel, ntp, anaconda, etc. which have nothing to do with branding as far as I'm aware.

Best Answer

CentOS is very close to being RHEL without the branding and support. In particular, the library versions are the same, so binaries that work on one will work on the other. The administration tools are the same and configured in similar ways. However, there are a few differences, as the two distributions sometimes apply different minor patches. For example, in this question, it was apparent that RHEL 5 and CentOS 5 apply different rules to identify files under /etc/cron.d.

In other words, at the level of your course, you can treat CentOS and RHEL as interchangeable. But if you needed to look up the precise behavior of a program in a corner of the man page, you may encounter differences.

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