Web hosting companies have no shortage of operating systems to choose from. From the old stalwarts like Debian, to its descendant Ubuntu, and from unusual alternatives like Gentoo, to distributions that are hugely popular among the geek contingent like Arch Linux, web hosting companies face an embarrassment of riches when it comes to choosing the foundation on which they will build their hosting platform.
Of course, part of the reason is that it’s a great distribution built on the YUM / RPM package manager. But the same can be said of Fedora, the free Linux distribution used as a testing ground for Red Hat features. The problem with Fedora is that it is a bleeding edge distribution that incorporates the most up-to-date software. While that might sound good to you and me, IT folks don’t think “yay, the latest and greatest.” They think “Ugh, untested and unstable.” RHEL is designed to appeal to people who think like this.
RHEL is a commercial distribution and only available with a support package from Red Hat. RHEL also contains a number of proprietary technologies and other intellectual property. CentOS is an “almost identical” copy of Red Hat Enterprise Linux without Red Hat’s proprietary parts. The developers of CentOS — who mostly work for Red Hat since the CentOS project was absorbed into the open source giant — endeavor to closely track RHEL versions, providing an identical experience without the price tag.
But why isn’t CentOS just another free distribution among hundreds? Because compatibility with Red Hat Enterprise Linux matters. RHEL is by far the biggest commercial distribution, and when third parties release software, including drivers, they release them for RHEL — CentOS is supported as a side effect of its compatibility with RHEL.
The important point is that CentOS is both free and RHEL-compatible. Most hosting companies have in-house system and network administration expertise and prefer to manage their own operating systems. They don’t need the support package, but they like the other benefits that come with RHEL.
Just as important is CentOS’ stability and long lifecycles. RHEL — and hence CentOS — is an enterprise-focused distribution and big companies don’t like change where operating systems are concerned. They expect them to work for many years without having to carry out potentially disruptive upgrades or re-installations — especially if they break compatibility with the company’s critical software. Bug fixes and security patches are enough.
CentOS moves slowly and has decade-long support cycles. The current version of CentOS — CentOS 7 — was released in 2014. It will receive updates as necessary until 2020 and maintenance updates until 2024.
In summary, CentOS is the preferred distribution of the web hosting industry because of its proven stability, its long support cycles, its compatibility with RHEL, its price, and because it’s a powerful operating system with a class-leading package manager.
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