Linux is popular in big business today. No longer, and not for a long time now, has Linux been the purview of the geek community but it is a solid, core piece of today’s mainstream IT infrastructure. That being said, Linux is still plagued by confusion over its plethora of distributions. This being the case I have decided to weigh in with some guidance for businesses looking to use Linux in their organizations.
For those unfamiliar with the landscape, Linux is a family of operating systems that are generally considered to fall under the Unix umbrella although Linux is legally not Unix just highly Unix-like. Individual Linux packages are referred to as distributions or distros, for short. Unlike Windows or Mac OS X which come from a single vendor, Linux is available from many commercial vendors as well as from non-profit groups and individual distribution makers. Instead of there being just one Linux there are actually hundreds or thousands of different distributions. Each one is different in some way. This creates choice but also confusion. To make matters even worse some major vendors such as Red Hat and Novell release more than one Linux distribution targeted at different markets, and within a single distribution will often package features separately. This myriad of choices, before even acquiring your first installation disc does not help make Linux uptake in companies go any faster.
In reality the choices for business use are few and obvious with a little bit of research. To make things easier for you, I will just tell you what you need to know. Problem solved. Now if managing your Linux environment could be so easy!
Before we get started I want to stress that this article is about using Linux for enterprise infrastructure – that is, as a server operating system in a business. I am not looking into desktop Linux or high performance computational clusters and grid or specialty applications or home use. This article is about standard, traditional server applications that require stability, up time, reliability, accessibility, manageability, etc. If you are looking for my guide to the “ultimate Linux desktop environment”, this isn’t it. Desktops, even in the enterprise, do not necessarily have the same criteria as servers. They might, but not necessarily so.
When choosing a distribution for servers we must first consider the target purpose of the distro. Only a handful of Linux distros are built with the primary purpose of being used as a server. If your distro maintainer does not have the same principles in mind that you do it is probably best to avoid that distro for this particular purpose. Server distributions target longer time between releases, security over features, stability over features, rapid patching, support, documentation, etc.
In addition to targeting the distribution in harmony with our own goals we also need to work with a company that is reliable, has the resources necessary to support the product and has a track record with a successful product. Choosing a distribution is a vendor selection process. There are three key enterprise players in the Linux space: Red Hat, Novell and Canonical.
For many Red Hat is synonymous with Linux, having been one of the earliest American Linux distributions and having been a driving force behind the enterprise adoption of Linux globally. Red Hat makes “Red Hat Enterprise Linux”, known widely as RHEL, as well as Fedora Linux. Red Hat is the biggest Linux vendor and important in any Linux vendor discussion.
Novell is the second big Linux vendor having purchased German Linux vendor SUSE some years ago. Novell makes two products as well, Suse Linux Enterprise and OpenSUSE.
The third big Linux enterprise vendor is Canonical well known for the Ubuntu family of Linux distributions. While the Ubuntu distro family includes many members we are only interested in discussing Canonical’s own Ubuntu LTS distribution. LTS stands for “Long Term Support” and is effectively Canonical’s server offering. Their approach to versioning and packaging is quite different from Red Hat and Novell and can be rather confusing.
Before we become overwhelmed with choices (we have presented five so far) we have one here that we can further eliminate. Red Hat’s Fedora is not an “enterprise targeted” distributions. This is a “testing” and “community” platform designed primarily as a desktop and research vehicle and not as a stable server operating system. To be sure it is extremely valuable and a great contribution to the Linux community and has its place but as server operating system it does not shine. Nevertheless, without Fedora as a proving ground for new technologies it is unlikely that Red Hat Enterprise Linux would be as robust and capable as it is.
We can also effectively eliminate OpenSUSE. OpenSUSE is the unsupported, community driven sibling to Novell SUSE Linux Enterprise. However, unlike Fedora which is an independant product from RHEL, OpenSUSE is the same code base as SUSE Linux Enterprise but without Novell’s support. This is a great advantage to the SUSE product line as there is a very large base of home and hobby users in addition to the enterprise users all using the exact same code and finding bugs for each other. Going forward we will only consider SUSE Linux Enterprise as support is a key factor in the enterprise. But OpenSUSE, for shops not needing commercial support from the vendor, is a great option as the product is the same, stable release as the supported version.
So we are left with three serious competitors for your enterprise Linux platform: Red Hat Linux, Novell Suse Linux and Ubuntu LTS. All three of these competitors are solid, reliable offerings for the enterprise. Red Hat and Novell obviously have the advantage of having been in the server operating system market for a long time and have experience on their side. But Canonical has really made a lot of headway in the last few years and is definitely worth considering.
Red Hat Linux and Suse Linux Enterprise have a few key advantages over Ubuntu. The first is that they both share the standard RPM package management system. Because RPM is the standard in the enterprise it is well tested and understood and most Linux administrators are well versed in its functionality. Ubuntu uses the Debian based package format which is far less common and finding administrators with existing knowledge of it is far less likely – although this is changing rapidly as Ubuntu has become the leading home desktop Linux distribution recently.
In general, Red Hat Linux and Suse Linux Enterprise have more in common with each other making them able to share resources more easily and giving administrators a broader platform to focus skills upon. This is a significant advantage when it comes time to staff up and support your infrastructure.
Ubuntu suffers from having a directly tie to a “non-enterprise” operating system that is particularly popular with the desktop “tweaking” crowd. Unlike Red Hat and Suse, Ubuntu is coming at the enterprise from the home market and brings a stigma with it. Administrators trained on RHEL, for example, tend to be taught enterprise type tasks performed in a business like manner. Administrators with Ubuntu experience tend to be home users who have been running Linux for their own desktop and entertainment tasks. This makes the interview and hiring process that much more difficult. This is in no way a slight against the Ubuntu LTS product which is an amazing, enterprise-ready operating system which should seriously be considered, but shops need to be aware that the vast majority of Ubuntu users are not enterprise system administrators and their experience may be mostly from a non-critical desktop focused role. It is rare to find anyone running RHEL or Suse Linux in this manner.
In my own experience, having software popular with home users in the enterprise also brings in factors of misguided user expectations. Users expect the enterprise installations to include any package that the users can install at home and that update cycles be similar. This can cause additional headaches although the Windows world has been dealing with these issues since the beginning.
At this point you have probably noticed that choosing either Suse and Ubuntu leaves you with the option of both free and fully supported versions, direct from the vendors. This is a major feature of these distributions because it provides a great cost savings and greater flexibility. For example, development machines can be run on OpenSUSE and production machines on Suse Enterprise lowering the overall cost if full support isn’t necessary for development environments. You can run labs from free versions for learning and testing or only pay for support for critical infrastructure pieces. Or, if you are really looking to save money or feel that your internal support is good enough, running completely on the free, unsupported versions is a viable option because you are still using the stable, enterprise-class code base.
Red Hat, as a vendor, does not supply a freely available edition of Red Hat Enterprise Linux. Instead, they make their code repositories available to the public and expect interested parties to build their own version of RHEL using these repositories. If you are interested in a freely available version of RHEL, look no further than CentOS.
CentOS, or the Community ENTerprise Operating System, is a code identical rebuild of RHEL. It is identical in everyway except for branding. CentOS is completely free – but unsupported. CentOS is used in organizations of all sizes exactly like a free copy of RHEL would be expected to be used and many businesses choose to run CentOS exclusively. As RHEL is the most popular Linux distribution in large businesses and as the commercially support version is rather expensive, CentOS also provides a very important resource to the community by allowing new administrators to experience RHEL at home without the expense of unneeded support.
Choosing between the Red Hat, Suse and Ubuntu families is much more difficult than whittling the list down to these three. In many cases choosing between these three will be based upon cost, application demands, existing administration experience and features. It is not uncommon for larger businesses to use two or possibly all three of these distributions as features are needed, but most commonly a single distribution is chosen for ease of management. All three distributions are solid and capable.
Another potentially deciding factor is if your enterprise is considering using Linux on the desktop. While RHEL can be used as a desktop operating system it is generally considered to be substantially weaker than Suse and Ubuntu when it comes to desktop environments. Because of this, Fedora is generally seen as Red Hat’s desktop option but this is not supported by Red Hat nor does it share a code base with RHEL causing support to be somewhat less than unified even though to two are very similar.
For mixed server and desktop environments, Suse and Ubuntu have a very strong lead. Both of these distributions focus a great many resources onto their desktop systems and they keep these components very much up to date and pay great attention to the user experience. For a small company that can manage to use only one single distribution on every machine that they own this can be a major advantage. Homogeneous environments can be extremely cost effective as a much narrower skill set is needed to manage and support them.
In conclusion: Red Hat Enterprise Linux, Novel Suse Enterprise and Ubuntu LTS, in both their supported versions as well as in their free versions (CentOS in the case of RHEL and OpenSUSE in the case of Novell, Ubuntu uses the same package) all represent great opportunities for the data center. Do not be lulled into using non-enterprise Linux distributions because they are cool, flashy or popular. Linux lends itself to being in the news often and to generating excess hype. None of these things are good indicators of data center stability. The data center is a serious business component and should not be treated lightly. Linux is a great choice for the corporate IT department but you will be very unhappy if you pick your backbone server architecture based on its popularity as a gaming platform rather than on its uptime and management cost.