CoreOS Stabilizes Cloud Container Linux Operating System

The container-based Linux operating system is now considered to be production-ready.


The open-source CoreOS Linux operating system hit a major milestone on July 25, issuing its first stable release. CoreOS is an Andreessen Horowitz-backed startup that offers the promise of a highly available operating system platform that is fully integrated with the Docker container virtualization technology.

Docker is an open-source technology that delivers a container approach to virtualization as an alternative to the traditional virtual machine hypervisor platforms.

CoreOS uses update channels, similar to client software applications such as the Google Chrome browser, Alex Polvi, CEO of CoreOS, told eWEEK. In that model, releases progress through each channel from alpha to beta and then stable. Alpha releases of CoreOS have been ongoing since August 2013, and CoreOS released its first beta on May 9.

"Once a release is considered bug-free, it is promoted bit-for-bit to the next channel," Polvi said. "Now that we have a stable release, this is the most tested, reliable and secure version of CoreOS."

For those users who want the newest software, Polvi said the alpha channel CoreOS release is the place, though that software is likely not the most tested. Polvi added that for those users who want to run CoreOS in a production environment, they should be using the stable channel because this version has been tested the most by the community.

"Essentially, every alpha is a release candidate for a beta, and every beta is a release candidate for a stable release," Polvi said. "This is how we ensure the updates to your server are the most secure, tested and reliable," he said.

In total, there have been 191 releases since development began on CoreOS, but the 367.1.0 release is the first to be considered production-ready—and thus tagged as stable. It includes a Linux 3.15.2 kernel and the Docker 1.0.1 container technology. In contrast, the most recent CoreOS alpha release, 386.1.0, provides the Linux 3.15.6 kernel and Docker 1.1.1.

In the typical Linux distribution model, once a release is labeled as being production-ready and stable, it is often set up for a long-term support model with multiple years of support. The CoreOS approach to stable Linux distribution support, however, is somewhat different.

"Updates in CoreOS are continuous, and this is a departure from the existing distro model of long-term support (LTS)," Polvi said. "When your server is always patched and up to date, support length becomes irrelevant, because you're always just running the latest version."

Going a step further, CoreOS already has a commercial support model in place called Managed Linux, which was first announced on June 30. The Managed Linux offering was revealed the same day the company announced that it had raised $8 million in its Series A round of funding.

"Anyone in the community can begin using the CoreOS stable release, but for those companies wanting commercial support for CoreOS in their environments, we offer Managed Linux," Polvi said. "With Managed Linux, CoreOS customers also receive a product called CoreUpdate, which is a dashboard that gives you the control of when you would like to update your servers."

Sean Michael Kerner is a senior editor at eWEEK and Follow him on Twitter @TechJournalist.

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.