Chapter 2: Choosing Your Distribution and Release Model

When we talk about Linux system administration, we probably jump quickly to wondering what flavor of Linux we are going to be talking about. This is typically the first topic that pops into our minds when having even a casual conversation with a business owner or someone in another, non-technical department. What we rarely spend much time thinking about is release and support models and how these play into our planning, risk, and expenditure models.

A quarter century ago we used to be educated regularly about the merits, caveats, and machinations of different software licensing models. Today terms such as open-source are used constantly and no one is surprised to hear them but like with all things technical as the adoption rate of a term increases the general understanding of it likely decreases. Therefore, we need to investigate some nuances of licensing as this plays a role in how an operating system will interact with the...

Understanding Linux in production

Linux is used in every aspect of business and production systems today. Simply by being a Linux-based system actually tells us incredibly little about what a device might be doing or how it might be used. Unlike macOS, which essentially guarantees that the use case is either a desktop or a laptop end user device, or Windows Server, which all but assures us that a system is an infrastructure or line of business (LOB) server. Having a system be built on Linux gives us very little to go on when looking to determine the intended use of that system. Linux is used on servers, in virtualization, in desktops, laptops, tablets, routers, firewalls, phones, IoT devices, appliances, and more. Linux is everywhere. And Linux is doing just about everything that there is to do. There are almost no roles that Linux does not cover, at least some of the time.

For the context of a book on Linux Administration, we are going to assume that we are talking about Linux...

Is Linux UNIX?

You'll likely hear people say that Linux isn't UNIX at some point in your Linux career. And to some degree, they are correct, but not in the way that they likely mean. Linux is only a kernel, one piece of a UNIX operating system. But operating systems built on Linux are, by and large, UNIX - at least according to the most definitive possible source, Dennis Ritche, one of the creators of UNIX. Linux implements both the UNIX approach and ecosystem, as well as the UNIX interfaces. It is a UNIX, just as FreeBSD and others are. UNIX is both a standard and a trademark. But the two are not necessarily maintained together. The waters are a bit muddy here. But standard Linux systems, any that we will be discussing in this book, implement the UNIX standard (known as POSIX originally and now a super set of POSIXs, known as SUS). So, they are a UNIX variant or derivative, just as Dennis Ritchie said that they were way back in 1999. He said the same thing about the BSD...

Linux licensing

Few discussions of Linux happen without the topic of licensing being mentioned. Mostly this happens for a few reasons: because Linux licensing is so different from nearly all of its competitors that it plays a significant role in business decisions, because it is the largest and most prominent open-source product on the market regardless of category, and because it arose in popularity in conjunction with the rise of the open-source software movement and quickly became its poster child. Most people instantly connect (and sometimes even confuse) Linux with any mention of open-source software, which leads to a lot of confusion as there are millions of other equally open-source software packages out there and when mentioning closed source software, no one jumps to any one comparable poster-child software package and assumes that that is what we are talking about. Linux, for whatever reason, gets treated differently than pretty much any other product on the market in how...

Key vendors and products

Unlike key competitors to Linux, such as Windows by Microsoft, macOS by Apple, Solaris by Oracle, or AIX by IBM, Linux has no single vendor representing it, but rather has quite a few vendors each providing their own products, support, and approach to Linux. This, of course, makes discussing Linux exceedingly difficult because Linux isn't a single thing, but more of a concept: a family of related things that often share many commonalities, but don't necessarily have to.

Describing the Linux family of operating systems is a rather daunting task as it is far more complex than just half a dozen sibling operating systems. In reality, Linux is a complex tree of root and derivative distributions with derivatives of derivatives and operating systems from all levels of the tree gaining and losing prominence over time. Thankfully, we can ignore the far more confusing and convoluted UNIX family tree of which Linux is just one branch! Analyzing the entire...

The myth of popularity

We must balance the idea of believing that just because something is popular that it will have a lot of support available in the market with the idea of practical support. Just because a product is popular or has many people offering support for it does not mean that support is better or easier to obtain in a practical sense.

For years, this is something that we have discussed about Windows and Linux operating systems. There were, and remain, far more Windows system administrators marketing themselves on the market than there are Linux administrators. But experience tells us that when hiring an administrator in the Linux world it is relatively easy to find at least reasonably qualified candidates. Run a series of interviews and almost every candidate will be able to do the job, even if not well. But run a similar interview looking for the exact same position but for Windows instead of for Linux and you will likely get twice or thrice the candidates to wade...

Releases and support: LTS, current, and rolling

Picking your vendor might seem like it gets you everything that you need to get started on your Linux deployment, but it does not. We still have to consider release management as part of our distribution decision plan.

A release model or release regime is an approach to how the distribution will update itself. There are three standard models followed by essentially all vendors. These are rolling releases, short term releases, and long-term releases.

Not all vendors provide all the different models. And each vendor approaches support differently. We will do our best to make useful generalizations, but when you make your decision you will need to consider the current strategies available from your prospective vendors as well as considering the quality of the support that they provide.

There is a second factor that is often confused with the release model, and that is the support period. The two are roughly related, but a vendor...

Choosing your distribution

Surprisingly, picking which distribution, or distro as it is commonly called in the Linux world, can be far more of a challenge than it seems like it should be. You might be lucky and work for a company that has a pre-determined Linux distro standard that you have to follow, and this question is already answered for you. This is becoming an increasingly rare scenario, though, as companies begin to realize the benefits of using the right distro for the right use case, and as it becomes better known that the idea that skills standardization just doesn't benefit from keeping systems identical as much as it was commonly assumed. But the practice still exists.

At the end of the day, it is essentially nonsensical to lead with operating system over workload choices. There is relatively little value in forcing a specific operating system choice and making application choices based on that. Of course, in an ideal world, all factors are considered and weighed...

Summary

We covered a lot in this chapter and a lot of seemingly unimportant factors that, I believe, tend to actually be pretty important in our roles in system administration. We learned how Linux fits into modern organizations and where it comes from historically which might give us some view into where it is going, as well. We dove into open-source licensing and how software licensing plays a role in how we work with our operating systems.

We took a look at who the big vendors are today and what key products they have on the market. Then we investigated release and support patterns both in general and specifically from the major vendors on the market today. And then we looked at putting all of those factors together to try to make a decision process for picking the best distribution for our workload.

In our next chapter we are going to be leaving behind the ten-thousand-foot views and we will be digging into the very technical world of System Storage Best Practices. This...