Near the end of 2020, Red Hat decided to kill CentOS as we know it... Kind of. We’ll get that a bit later. But for now, let us look take a look at what Red Hat Enterprise Linux is and take a look at all of the clones and forks that we have available to us. So let’s get to it.
Red Hat Enterprise Linux
Red Hat Enterprise Linux, or RHEL for short, is a Linux distribution developed by, believe it or not, Red Hat. RHEL is an RPM based distribution that uses the DNF package manager and follows a more LTS like release cycle, with an older package base. RHEL’s package base actually comes from earlier versions of Fedora which makes Fedora a testing ground for different changes they may come to Red Hat in the future. For example, the current latest version of RHEL 9.0, is based on Fedora 34 from March 2021. Do note though, that while Fedora is sponsored by Red Hat and uses some Red Hat infrastructure, Fedora is still its own project that may make decisions against Red Hat. Another thing that makes Red Hat special is that a lot of modern technology in the Linux world is either significantly funded by Red Hat, or ran or heavily contributed to by Red Hat developers,.. A bunch of examples of this include GNOME Shell, SELinux, SystemD, PackageKit, Wayland, D-Bus and many other projects. However, another thing that made Red Hat different is that it’s a paid Linux distro but paying for it gives you support and docs from the Red Hat company.
This is where CentOS came in. Because Red Hat was a paid distro, and people may be fine with community support/docs instead of official Red Hat docs, a rebuild of RHEL was formed called CentOS. CentOS essentially took Red Hat’s source code, removed Red Hat branding and added it’s own repositories, and then compiled it themselves. So if you needed Red Hat, and didn’t care about the support from the company, you would just installed CentOS. Red Hat later bought the project out, and things continued running smoothly. But as mentioned earlier, Red Hat decided to stop supporting CentOS halfway through CentOS 8’s release cycle, and many people consider that to be the death of CentOS. This resulted in many new RHEL rebuilds and clones coming out including Alma Linux, Rocky Linux, and more that we will get into later.
However, CentOS’s death was kind of overblown because CentOS Stream replaced it, and what stream was, was severely miscommunicated to the community. CentOS Stream was essentially just Red Hat, but with one huge difference. Instead of small fixes and changes needing to make it’s way into first RHEL, and than rebuilt into CentOS. They would be implemented into CentOS Stream first and than RHEL second. This made contributing to both CentOS and RHEL much easier because you wouldn’t have to deal with the bureaucracy that comes from trying to contribute to a paid Linux distro. The issue with the communication was that they kind of pushed Stream as a completely different thing. Not many people know how Stream actually works, and Stream is just horrible branding because it makes it sound like a bleeding edge rolling release distro. They also killed CentOS 8 halfway through its normal life cycle and made people “migrate” to a whole new branch of CentOS. Not a good look for something that was supposed to be an LTS distro. I think of would have been better if they just made this change in CentOS 9 without a whole rebranding or kept CentOS Stream as a separate thing completely.
However, the damage from the bad rebranding of CentOS Stream has already been done, and there are now loads of options if you want a good Red Hat Enterprise like Linux experience. So, let’s look at each of them and find out which one may be the best for you.
Red Hat backed
Let’s talk about the 2 official projects backed by Red Hat, both of which we already mentioned. CentOS Stream and Red HatmEnterprise Linux. Believe it or not Red Hat offers a free program for individual users. This does have a few limitations. For example,you are only able to register 16 systems running RHEL, but you also gives you access to all of RHEL’s releases, as well as their documentation and resources for learning how to use RHEL. If you are trying to learn how to use a Enterprise Linux system like this, I would recommend learning with the RHEL Free plan because it gives you access to all of the same documentation and self-support resources that you can get from paying for Red Hat. However, if you want to use RHEL for a personal use-case, I recommend another system because RHEL Free is kind of a hassle to setup. Mainly because you still need to make an account to download it, and once installed you need to register it with an entitlement server.
CentOS Stream on the otherhand is still a great option if you need an RHEL-like server, although it isn’t an exact clone like a lot ofthese other distros are. While CentOS Stream for the most part will function almost the same as RHEL, since it is used adevelopment ground for RHEL, it won’t be 100% bug for bug compatible with RHEL. And I’ll get to what bug for bug compatible means later. The point is, if you want something like a web server or would like to self host something, and you would prefer to do itwith a distro in the RHEL-family compared to something like Debian or Ubuntu, than I think CentOS Stream is one of the bestoptions to look at. You still get rock solid stability, it’s close enough to mainline Red Hat that you won’t need to relearn much, if anything at all, and you will get bugs fixes and other minor updates slightly faster than regular RHEL.
Community Backed RHEL Rebuilds
Next up let’s talk about some of the community backed rebuilds of RHEL. Some of these may have some small bonus features, butfor the most part, they are RHEL with different repos, a rebrand, and community support instead of corporate support. All of theseshould also be bug-for-bug compatible with RHEL, which means that the vast majority packages should be identical to aninstallation of Red Hat. If a bug exists in RHEL, it should also exist in these rebuilds.
Let’s start with Rocky Linux. This is a distro that emerged in the aftermath of CentOS’s death and aimed to fill in the void thatCentOS left. It was started by one of the co-founders of CentOS, Gregory Kurtzer. It was named Rocky Linux to honor another co-founder of CentOS who died, Rocky McGough. The company that runs it is called the Rocky Enterprise Software Foundation, andthey are structured as a Public Benefit Corporation. But because it technically is a corporation it does move slower than other distroslike Alma, which came with it’s rebuild of RHEL 9 more than a month before Rocky Linux.
Speaking of Alma Linux, that’s the other CentOS replacement that came out of the death of CentOS. This was started and heavily funded by CloudLinux but it became a community project that also has funding from a lot of major companies such as AWS, ARM,and Microsoft. Unlike Rocky Linux, and despite it being started by CloudLinux, Alma is ran by a 501 non-profit. It also seems to get releases faster than Rocky Linux with only 9 days between RHEL’s 9.0 release and Alma’s 9.0 release, and because it having more backing, as well as faster release schedules and other factors, it has kind of become the most popular community based RHEL clone.
Corporate Backed RHEL Rebuilds
Now let’s look at some other options that are corporate backed and not community ran projects. Most of these have gotten an earlierstart and have existed for years before the death of CentOS.
Let’s start with probably the biggest corporate backed alternative and that is Oracle Linux. This is another rebuild of Red Hat with replaced branding for the most part. However do keep in mind that it is not 100% binary compatible, and there are some differences with some of the packages. For example, Oracle ships it’s own quote “Unbreakable Enterprise Kernel” with newer kernel versions and some performance enhancements, although a RHEL compatible kernel is offered. There’s also some differences in other core components too such as glibc, openssl, among other things.
Another corporate backed distro is EuroLinux. This is a RHEL rebuild backed by the company EuroLinux. It is 1:1 bug for bugcompatible with and RHEL and EuroLinux the company does provide support for EuroLinux the distro. They also have migration scripts to migrate RHEL, CentOS, Oracle Linux, Rocky, and Alma to EuroLinux. They do have a free version that you can use as aRHEL rebuild, but they also have a paid version that provides you access to RHEL 6 and 7 based versions of Euro Linux, fullsupport, access to additional intermediate packages and documentation.
Finally, VzLinux which is a RHEL rebuild owned by Virtuozzo made to be a base for their own operating systems such as OpenVz. Itis 1:1 bug for bug compatible with Red Hat but other than that there’s not much going on that can differentiate it from Alma and Rocky. It does have multiple flavors, with the standard bare metal version but also a special version for containers and virtual environments. It also has a feature called Chameleon, which edits the os-release file to look like either RHEL or CentOS. This is good if you are trying to run software like CPanel that will only install on distros that it supports like Alma. However, I kind of have a feeling with this distro that Virtuozzo is only maintaining it, because they use it themselves. Outside of it’s own product line, there’s very little amount of documentation for it, updates are slow, and the website for it feels more like a landing page than a website for a distribution.
Now those are the main distributions that can be used as drop in replacements for CentOS, so let’s talk about some other distributions that will give you a similar experience, but I may not recommend them for various reasons.
Navy and Circle Linux
Let’s start with Navy Linux and Circle Linux. Navy Linux is another Red Hat rebuild ran by a Delaware non-profit. The reason I don’t recommend Navy Linux isn’t because of any issues with the distro itself, but more because it is too small of a project in my opinion. It only has a few corporate sponsors, it’s GitHub only has 5 repositories, and only 2 of which have been updated in the last 30 days as of October 9th 2022, and of those 2 repos, one of them is the website, and the other is just docker images. And as of the time of this video, Navy Linux still doesn’t have a rebuild of RHEL 9 out yet, and it’s website has a noticeable lack of information. CircleLinux is a bit better, this is a Chinese-based community ran project and it’s actually backed by Huawei and Tencent. However; it tookthem quite a while to come out with their rebuild of RHEL 9, and there’s really not much about it that makes you wanna use it over Alma or Rocky. Both of these are binary compatible with RHEL, but in general since they’re much smaller than these other distros you won’t be seeing as many guides and community support available for these distros, and honestly, I don’t see these 2 distros lasting that long.
The last honorable mention is Fedora. Fedora is a honorable mention simply because it can not replace Red Hat, but for a lot of use cases it’s a good option and the system structure is very similar to RHEL. Fedora is upstream for CentOS Stream before CentOS Stream becomes Red Hat, so brand new Fedora releases contain a lot of tech and features that may become part of a future release of Red Hat. It’s also worth noting that because of this relationship, a lot of the structure of a Fedora system is similar to either current or future Red Hat releases and some people even consider it being a part of the RHEL family because of this. But, very important, do keep in mind it is not even close to being binary compatible with Red Hat because of it using newer packages. However, if you would like to run a server with newer packages, but still want it to feel like Red Hat and CentOS, this is the way togo. I’ve always recommended this as a desktop distro, but even for server use cases where you need newer packages, it’s a verysolid distro to go to.