Platform Decisions - OS Choices

Following up on my previous discussion around platform decisions and solution architecture, I wanted to dive into Operating System (OS) choices. This is a difficult choice for many companies because of competing priorities, experience, training levels, costs and ultimately faith to one OS or another. Choosing an OS for production use is also a difficult choice because the options change so frequently, and the applications you will ultimately use may not work with your preferred choice of OS.

With most companies, this is rarely a discussion around which OS will be used exclusively. More often it is a discussion around which OS will be added to or eliminated from the infrastructure to either lower administration costs, lower maintenance costs or increase capabilities. Often, companies also break down an OS choice into groups, either server and desktop class systems, or by departmental needs. This separation can be very beneficial when discussing any changes; it allows the folks doing the assessment to clearly define needs and balance them based on focused groups, trying to balance needs across a large company can often prove to be difficult to impossible.

Primary Reasons for Change
First, lets explore the primary reasons a company would change the mix of OSs already in use within the IT organizations.

Lower Training Costs: Today Linux is the predominant OS within the Education communities. This creates an environment where new staff entering the work force are very experienced and knowledgeable on working with Linux based systems. This is important because by using an OS that potential staff are experienced with limits the training that is required to get and keep them proficient at system administration. Companies will often eliminate an OS from use because staff skills are not at a peak for it, and costs to keep them trained at appropriate levels continue to rise as an OSs dominance disappears. This was primarily seen with the large UNIX variants (Solaris, HP-UX, AIX), over time companies have limited the use of them because students were no longer coming with these skills from college, and existing staff were spending more and more time keeping up with training on these platforms.

Increase Performance: Performance is often a primary reason to evaluate utilizing a new OS. Most application vendors today support a very narrow sub-set of the available OSs on the market. Because of this, they must focus there resources on tuning and performance enhancements, at times companies can get a 20% to 30% improvement in application performance by moving the application to a better supported and tuned OS.

Lower Maintenance Costs: In todays world where Open Source is becoming more and more dominant in the business world, companies are reviewing there traditional support and licensing modes. There is a multitude of options available today from OSs that have no cost to use, to OSs that charge for all used instances. A company with legacy OSs in place has an opportunity to review how they negotiate support contracts with these new models so that they are paying for an appropriate level of support for all systems.

Increase Capabilities: Being able to provide a new capability that was previously not available is a large reason companies look to adding new OSs to there existing enterprise. Todays applications vendors rarely support all possible operating systems, more often then not, they choose a subset of OSs that they feel will best cover there potential market. Companies are constantly evaluating new applications for potential benefits to the companies bottom line, as part of this, often times a new OS must be brought in for the administration team to manage to provide new capabilities by adding new applications to the enterprise.

Assessment Questions
Second, lets look at some questions that can be asked when assessing possible OSs for use in your environment:

1. Why am I assessing my current install base of OSs? What is the goal of any changes?
2. What is the current cost, both in licensing and training, for all current OSs we have deployed?
3. What OSs are our staff skilled at administering? Both current utilized and non-utilized OSs.
4. For any new OSs we are assessing, what will be the training cost to get staff proficient at maintaining them? The yearly cost to keep our staffs' skills up to date?
5. What level of OS support can be provided by in-house resources and what will need to be included with any purchased support agreements?
6. What tools currently in place will need changes or license upgrades to support a new OS?
7. Will this OS introduce security vulnerabilities that will be unreasonably difficult to manage?
8. Is this system mission critical? Can the system utilize an OS with just community support and no formal SLAs?

Lets also look at some questions that can be used to asses if an existing OS should stay part of the enterprise or should be phased out:

1. What is the yearly cost in support for this OS by itself? In relation to other OSs within the company?
2. What percentage of staff in house are proficient on this versus other OSs?
3. What is the support cycle for this OS? How much longer will the vendor provide patches without additional support contract costs being incurred?
4. Does the vendor, both OS and application, provide a supported upgrade path to a newer version?

These questions can guide an informed decision about future OS choices. It is critical to understand the financial trade offs that each OS will introduce, including training costs, licensing and support costs, hardware costs and performance capabilities. Every OS has it's own specific details including cost of acquisition, cost of administration, cost of support, etc. These questions should be weighed against currently in house OSs, as well as new OSs that are potentially being considered for addition to your environment.

In addition to the financial questions for each OS, a company must consider the life cycle of the OS. Most OSs have formal release schedules for patches, upgrades and subsequent versions. It is important to evaluate any new OSs with these details in mind. It can end up being quite costly if an OS hits its end of life and you have to rapidly stop using it and migrate the work load to another platform, where as be carefully evaluating the roadmaps for the OS, you can make an informed decision that will successfully work with your in-house processes for support and upgrades.

Making a choice to add or eliminate an OS within a company can be a difficult one, both because of personal territorial issues, as well as complicated technical needs. It is important to focus on the true costs to the company related to the decision, this will ensure that training, implementation, licensing and support are factored in and staff fully understand the costs and ultimate decision.