While experience and knowledge are always more valued than mere certification, it is often useful to have a certificate to quantify knowledge to a certain degree. So what are your choices if you wish to get Linux certified?
CompTIA conducts foundation level exams to certify basic proficiency, the ability to manage Linux systems using the command line, perform admin functions and software configuration and manage server systems and security. A pass suggests experience equivalent to six to twelve months. It's called the "Linux+".
Moving up there is the (non-profit) Linux Professional Institute for people with a richer experience. There are three levels of credentials, the LPIC-1, LPIC-2 and LPIC-3 - all demonstrate expertise without tying the knowledge down to a particular distribution. The LPIC is a better demonstration of skills but top professionals aren't allowed to jump directly to LPIC-3 without passing the first two stages. Further, these qualifications expire after five years and need to be revalidated. LPI training material and sample exams are available through Google and through LPI resources (IBM offer some resources too). You could also take a Ubuntu Certified Professional exam (after passing LPIC-1).
Linux certification is obtained by completing three levels of tests, both with two exams each. These exams range from various topics and each exam is progressively more difficult than the last. The exams can be completed in any order, but in order to move to the next level of exams, the previous two exams must be completed. The three levels of certification are as follows: Junior Level Administration, Advanced Level Administration, and Senior Level Administration. These levels are taken from the Linux Professional Institute. There are many levels of certification, depending upon the company used. The two tests which are administered at the Junior Level are aptly named 101 and 102. These tests consist of working at the command line, performing very basic maintenance tasks, and installing and configuring a workstation and connecting it to an existing network. Once a person has shown proficiency at these tasks and passed the test, they then move on to the Advanced Level Administration for certification. The Advanced Level of certification deals with advanced training, such as the ability to administer a small or medium sized site which contains both Microsoft and Linux servers. The test also tests for the ability to supervise assistants and advise upper management. If these tests are passed with proficiency, the person is then qualified for the next and last round of testing, which is also the last. The Senior Level of certification brings all previous training together under two tests which are named 301 & 302. It is advised by this level in the testing process, the person have expert knowledge on many Linux kernels, including Knoppix, Red Hat, Ubuntu and others. Once the person has demonstrated proficiency in various levels of testing, they are rewarded with the Senior Level of certification from the Linux Institute.
The Linux Professional Institute does not provide any official learning materials, but there are several resources on the internet which provide training for tasks which are outlined in the above exams. Some of these materials include tutorials, practice exams, preparation guides and study materials. These resources are freely available for those who need them and can be accessed via many different means, including the internet, the library, etc.
Some of the more popular resource sites include PenguinTutor, a site which is dedicated to providing information, as well as tutorials and practice exams relating to the Linux Operating System. These study materials include all flavors of Linux, from Red Hat, Knoppix, and Debian. The site is very well maintained and provides a wealth of information for those seeking their Linux Certification. Another useful resource site is Happy Monkey, which is written and maintained by David Horton after he obtained his own LPIC-1 certification. It contains well written notes and a hugely helpful study guide for LPIC-1 certification. This study guide is available in both HTML and PDF formats.
Redhat have their own Red Hat Certified Engineer program, a self titled "crown jewel of Linux certifications" (in addition to the Red Hat Certified Security Specialist (RHCSS) and Red Hat Certified Architect (RHCA)). The certifications range from the esoteric RH033 (Linux essentials) to the RH302 (compare). To pass RedHat exams it's a bit more involved. Unlike the other two, it isn't simply a matter of taking some multiple choice questions. The exam is very hands on and practical oriented and examinees are expected to work in live environments with real systems. As with the LPI qualifications, the RedHat ones expire but in a slightly different manner. They are valid till after the second major release following the exam taken. These exams are also significantly more expensive to take.
Novell offers various levels of certification from the Novell Certified Linux Administrator (CLA) through the Novell Certified Linux Engineer 10 (Novell CLE-10) to the Novell Academic Instructor.
MySQL offers their own certificates ranging from the entry level Associate (CMA) to the Developer (CMDEV) and DBA (CMDBA) which requires two exams to the MuSQL Cluster Certification.
Those are pretty much the big players. There are thousands of other resource available for those who are seeking Linux Training in order to get Linux Certified. The most popular of these websites is the Linux Training Database, which outlines over 719 training centers across the globe, not to mention several methods of internet based training.
For those seeking more resources for their Linux Certification tests, you can browse the web or search the above sites. There are several more resources which are available on the web to help you gain your certification. See also our Linux training resource.