Converting CSL RedHat Enterprise Linux computers to CentOS

Fri, 05/05/2017 - 10:47am -- dparter


CSL managed RedHat Enterprise Linux computers will be switching to CentOS (a free rebuild of source packages from the Red Hat Enterprise Linux). This is necessary due to the expiration of the RedHat licenses that were donated to us through a partnership between RedHat and the HTCondor project.

The conversion will take place during the week of May 22. The conversion will not require a reboot. A more detailed schedule will be announced prior to the conversion.

A kernel upgrade will be scheduled after the completion of the CentOS conversion. This will require a reboot of all managed CentOS (previously RHEL) computers. We expect to do the kernel upgrade the week of May 29.

More Details:

RedHat and CentOS:

For the past several years, the CSL has been providing RedHat Enterprise Linux (RHEL) on our managed workstations. This was made possibly by a partnership between RedHat and the HTCondor project. Prior to that, we used CentOS, which is a free rebuild of the open source packages used in the corresponding RedHat Enterprise release. The free licenses are no longer available, so we are switching our RedHat computers to CentOS.

In our testing, the conversion from RHEL to CentOS has been smooth, with very few user-visible differences. We do expect a few surprises, however, and will do our best to address them as they arise.

The RHEL licenses (and support, including access to security updates) expire on May 18. That means that we have very little flexibility in scheduling the conversion. We would have preferred to make this change several months before the deadline, but due to staffing issues, that was not possible

If you have any concerns about the conversion timing, or special situations that we need to be aware of, please send email to and we will work with you to try to mitigate the risk of the conversion.

CSL Linux roadmap: Ubuntu and CentOS

RHEL (and CentOS) are "enterprise" releases, committed to long-term support and stability in component versions. This is very helpful for enterprise service providers, but not the best choice for the Computer Sciences Department, where we often need the latest versions of various components of the system. For that reason, and to improve flexibility for research projects, the CSL is switching our primary Linux distribution to Ubuntu. The instructional labs and many desktop linux workstations have been running Ubuntu since last summer.

RHEL/CentOS 6 was released in 2011, and is aging. The CSL will phase out support for CentOS 6 as soon as possible.

CentOS 7 was released in 2014. It is not a very good desktop distribution. We intend to phase out desktop support for RHEL/CentOS 7. Server support may continue. We will consult each research group using RHEL/CentOS 7 and collaborate on a support plan.

Ubuntu LTS 16.04 was released in 2016. Ubuntu 14.04 desktops will be upgraded this summer. The Instructional Linux labs will be upgraded before the start of the 8-week Summer Session.