CentOS Linux is a Linux distribution derived from the Red Hat Enterprise Linux. Because it is free, CentOS Linux is widely popular with Linux users, web hosts and small businesses. However, as with most free things, you do give up something. In this case, there is no direct CentOS support services offered by the CentOS team. So before you select CentOS for your next project, there are a few things you should know about using CentOS Linux.
Personally, I used CentOS for some of my projects, but there are some growing concerns about using it for commercial purposes. At many hosting providers, the cost difference between CentOS and Red Hat Enterprise Linux is minimal. In these cases, I recommend you select RHEL.
1. CentOS is not Red Hat Enterprise Linux
CentOS is a repackaged version of Red Hat Enterprise Linux. The CentOS team is a volunteer group that repackages publicly available RHEL source packages into binaries. The software is then distributed through various public mirrors. To my knowledge, there is no direct relationship or partnership between CentOS and Red Hat. The lack of this formal relationships has created problems in the past, such as a when Red Hat demanded all Red Hat branding be removed from CentOS.
h3. No Official CentOS Support
While there are a number of companies that support CentOS Linux, there is no official, commercial support service. With RHEL, you get support directly from Red Hat. With CentOS, you rely on the community or IT consultants for commercial CentOS support.
2. Lag Time for Major Releases
Historically, when a major version of RHEL was released, CentOS was soon to follow. More recently, the lag time has increased. In the case of the most recent releases, some 200 plus days went by before CentOS 6 was rolled out.
(Tip: Learn how to check which version of CentOS you are using.)
3. Playing Catch Up
As the StandAlone SysAdmin puts it, CentOS is always playing catch up. The CentOS team cannot rebuild packaged until Red Hat releases them. So CentOS and any other repackaged version of RHEL is going to lag behind the commercial product. Typically this is not a major issue, but when critical security issues are discovered and made public, you need updates quickly. If you have contracted someone to provide CentOS support, they cannot do anything until the CentOS group rebuilds the packages.
4. No CentOS Certification Programs
Red Hat provides certification and training programs to help professionals learn about and support their products. There are no such formal programs for CentOS support. Due to the similarities of the OS’s, someone trained to support Red Hat Enterprise Linux can support CentOS Linux. However, some companies may require the use of certified support staff. In such cases, I am not aware of anyone providing CentOS Linux certifications.
5. Team Hiccups
As with many open source projects, team members can go missing or have new obligations. In most cases, the team are simply volunteers. They are not paid. A team member’s personal commitments can easily delay bugs getting fixed. This has happened at CentOS and is worth considering when selecting this distribution as your operating system.
6. Thank You CentOS
Do I still use CentOS? Yes. The ability to leverage my Red Hat expertise with a very similar OS is terrific. There are other alternatives emerging, such as Oracle and Novell Linux, I will stick with CentOS until I have more reasons to change. If I do switch, I suspect I will just pay for the RHEL subscriptions.