Understanding the CentOS flow • The registry
Red Hat released CentOS Stream 9, the first major release since the company rocked its community hard by announcing it was ending traditional CentOS a year ago.
This is the second iteration of the new CentOS Stream distribution, and the IBM affiliate is likely hoping that it will provide a more attractive migration route for CentOS users than for them to get off the ship.
Notably, in CentOS Stream 8, HR application streams – analogous to Fedora’s “scalability” – were mandatory, but they are optional in 9.
It’s a big deal in the world of Red Hat, but it can be a mystery to the millions of non-Red Hat Linux users. Since it seems to appeal to Red Hat to imagine that Red Hat is the entire Linux world, its official docs don’t really give you any context, so The register will try to translate for you.
The original Red Hat Linux (RHL) was released in May 1995, making it one of the oldest distributions, but the company killed it after version 9 in 2003. RHL was replaced by Red Hat Enterprise Linux (RHEL), which became the only supported distribution. Word supported is the key here.
The pre-existing Fedora project, formerly a third-party repository for RHL add-ons, has been upgraded to free and unsupported community distribution: no paid support, updates for 13 months, a new version about twice a year and upgrades switching from one version to another can be tricky, although it’s a lot better now.
Fedora tends to be fairly forward thinking compared to most regular release cycle distributions – which is why the code word “innovative” features heavily in the project’s mission statement. The Reg have loved Fedora for a long time. The new gloss that works in Fedora, when it ends up being boring and stable, goes into RHEL. As RH puts it, Fedora is “upstream” of RHEL.
RHEL, on the other hand, was and is commercial: you can only get RHEL by buying it, which actually means buying a support contract. But it’s still FOSS, which means HR is legally obligated to make the source code available. So anyone – not just customers – could download the Red Hat source code packages for each package for free in RHEL, and recompile them all to create a free RHEL clone.
Various third parties have started doing this and producing independent RHEL-compatible distributions, such as Scientific Linux (from FermiLab) and White Box Linux (from the Beauregard Public Library in Louisiana). The largest of these, CentOS (Community Enterprise OS), debuted in 2004.
The idea of these distributions is that they are basically the same as RHEL, but with changed names. Not just the same commands, but the same versions of the same binaries, with the same configuration files, in the same directories, for full compatibility. Whatever fixes RHEL obtained, the rebuilds were also made shortly thereafter. You can learn how to use a free prototype and test it out, but deploy on the real thing. Theoretically, if you didn’t want to pay for a lot of RHEL licenses, you could pay for a copy, get official support, but run all your other boxes on CentOS and register a package. You only get official support for one copy, but the same methods and tools work on all of them.
Oh, and in 2006 that well-known FOSS friend Oracle stepped into the game by doing another such rebuild. This is often known as its help desk (paid, optional, and significantly cheaper than the official Red Hat Network help desk): Oracle Unbreakable Linux.
It was all good, clear and easy to understand. Sometimes RH tried to make life difficult for the cloners, but they survived. Despite them, RHEL was a huge success – in 2011, RH was the first billion dollar Linux vendor.
The beginning of the end
Then, in 2014, RH did something very strange: it brought CentOS in-house. So now the main freebie was sort of officially sanctioned. Not supported, but given the nod. Please pay RHEL for your production enclosures, but if you prefer not to, you can run CentOS Linux for nothing.
This was, obviously, very good for CentOS – but very bad for the other rebuilds, and as a result most of them (with the exception of Oracle) shut down.
This left RH with an odd array of distribution offerings. Before 2014, the positioning was clear: freeloaders had Fedora, and had to update themselves regularly. If you wanted help, you paid for RHEL. After 2014: if you want stability and support, please buy RHEL; if you don’t want to pay, well, there’s our free and fast community distro… or, you could have this nice, stable distro that’s the same as RHEL, and it’s free, you just don’t get any support. Indeed, the company offered a free product specially designed to compete with its own commercial flagship.
Compare that to SUSE’s easier-to-understand proposition: You can download a full, fully-functional evaluation version of any of its products, but you only get a 60-day trial period. After that, more updates.
Or run openSUSE Leap for free, which has the same release cycle as SUSE Linux Enterprise. If you want support, for a price you can migrate from Leap directly to SUSE Linux Enterprise.
It took RH about five years, but eventually he seemed to realize it. In the company’s words, CentOS Linux was “downstream” from RHEL; although the word “community” was prominent on the CentOS site, there was no way to contribute: it was a simple rebuild of RHEL.
The first visible result has been a new direction for CentOS, with CentOS Linux 9 canceled and CentOS Linux itself replaced by CentOS Stream in 2019.
Rather than duplicating RHEL’s release cycle, the new Stream edition receives a continuous stream of updates. Critically, this means that it is no longer an exact duplicate of RHEL; from a sales perspective, it is no longer in direct competition with its parent product.
For the company, all is well. Presumably, this did not tempt many CentOS Linux users to cross the stream, as just five months later the company announced that the end of life of CentOS Linux 8 was being changed from 2029 to 2021 – 36 months earlier. than version 7.
As usual, RH prefers to phrase this in terms of upstream, downstream and communities. Previously, RHEL was downstream of Fedora and CentOS Linux was downstream of RHEL. Now CentOS Stream is downstream of Fedora and RHEL is downstream of CentOS Stream.
Rich Bowen of the company told us, “From my As a community manager, CentOS Linux was not open source, was not a collaborative project, and was not really a community in any meaningful way. CentOS Stream gives us the opportunity to make CentOS a real community project, with a real path of contributor / collaborator. “
Which is commendable and quite understandable. In principle, migrating from CentOS Linux 8 to CentOS Stream 8 is as easy as two commands:
dnf swap centos-linux-repos centos-stream-repos
RH also offers a tool to migrate from CentOS Linux directly to RHEL, which seems considerably simpler than the documented upgrade path from RHEL 7 to 8.
Interestingly, Bowen told us, “If people to want Where need (or think they do) a RHEL 1: 1 rebuild… we’re working closely with Alma to make sure they have what they need. “
This even extends to major version upgrades: “At the moment we don’t have a Stream 8 to 9 migration tool. However, the folks in Alma are working on ELevate which will have this as a feature.”
Red Hat made a mistake in adopting CentOS. CentOS Linux fans may not agree, but for all the heartache it has caused, the current steps are fixing the mess the company has made for itself. RH is doing everything in its power to provide CentOS Linux users with a choice of migration paths, including making it easier for users to switch to Stream.
The stream itself should offer smaller, less spectacular updates and be more competitive with other server distributions, for which Fedora frankly has never been an ideal choice. It also gives the inhabitants of the Hativerse a way to get information about the direction of RHEL. And it’s especially nice to see Big Purple cooperate with other distros. ®