Red Hat's Certified Engineer (RCHE) title has the high-end Linux certification market to itself (its performance-based lab components ensure that it will avoid being cheapened by those candidates with little hands-on experience).

On the introductory level, two options are Linux+ from the Computer Technology Industry Association (CompTIA) and the Linux Professional Institute's LPI Level 1 title (Levels 2 and 3 are under development.). I recently completed both.

While both programs have similar aims, each is different in significant ways. The Linux+ exam, which is a single, two-hour test, is intended for someone with around six months of Linux experience. The LPI Level 1 exam is aimed at introductory- to intermediate-level Linux administrators. LPIC Level 1 certification requires passing two 90-minute exams.

Not unexpectedly, the two certifications cover many similar areas. However, what does surprise me is the substantial difference in knowledge each requires. For example, apart from a couple of notable examples, Linux+ is happy to ask which command to use in a given situation, while the LPI exams expect you to know the meaning of many common options for each command as well. Whereas the Linux+ exam was interested in having the participant know when custom kernels need to be built, the LPI exams expected you to know exactly how to build and install a custom kernel -- what steps are involved and what each step actually achieves.

As well as the greater depth of the content required in the LPI exams, there are also more areas covered. I would have preferred to see fewer basic hardware questions in the Linux+ exam, leaving more room to ask about Linux concepts. Of course, as an IT professional you need to know this hardware information, but I don't see why this needs to be tested within a Linux certification test.

I don't mean to belittle the Linux+ exam: You won't be able to fake it if you don't know your material. But the LPI Level 1 exams really aim to ensure that the candidate can get around a Linux system. Even so, I suspect over time the Linux+ certification will prove more popular because so many of us are already aware of CompTIA's other certifications.

I started out on my Linux certification journey as a structured way to learn more about Linux. To that extent I've certainly achieved my personal objectives: I feel like I know enough to be competent; yet at the same time I have a healthy respect for what I still don't know. One day I may go ahead and complete my RHCE, but now I'm too busy with other plans outside of work to find time for that.

What do you think about Linux certification? Does it have any value at all? Are you planning to get a Linux certification -- and if so, which one? Post your comments below so we can all read your thoughts.