We have envisioned this case study to approach all modern information system services currently used in a medium sized company. After reading this book, you will have all of the elements necessary to install Debian on your servers and fly on your own wings. You will also learn how to effectively find information in the event of difficulties.
2.1. Fast Growing IT Needs
Falcot Corp is a manufacturer of high quality audio equipment. The company is growing strongly, and has two facilities, one in Saint-Étienne, and another in Pau. The first has around 150 employees; it hosts a factory for the manufacturing of speakers, a design lab, and all administrative office. The Pau site, which is smaller, only has about 50 workers, and produces amplifiers.
NOTE Fictional company created for case study
The company, Falcot Corp, studied here, is completely fictional. Any resemblance to an existing company is purely coincidental. Likewise, certain example data throughout this book may be fictional.
The computer system has had difficulty keeping up with the company's growth, so they are now determined to completely redefine it to meet various goals established by management:
modern, easily scalable infrastructure;
reducing cost of software licenses thanks to use of Open Source software;
installation of an e-commerce website, possibly B2B (business to business, i.e. linking of information systems between different companies, such as a supplier and its clients);
significant improvement in security to better protect industrial secrets related to new products.
Underlying these goals, the entire information system will be overhauled.
2.2. Master Plan
With your collaboration, IT management has conducted a slightly more extensive study, identifying some constraints and defining a plan for migration to the chosen Open Source system, Debian.
A significant constraint identified is that the accounting department uses specific software, which only runs on Microsoft Windows™. The laboratory, for its part, uses computer aided design software that runs on MacOS X™.
Figure 2.1. Overview of the Falcot Corp network
The switch to Debian will be gradual; a small business, with limited means, can not change everything overnight. For starters, the IT staff must be trained in Debian administration. The servers will then be converted, starting with the network infrastructure (routers, firewalls, etc.) followed by the user services (file sharing, Web, SMTP, etc.). Then the office computers will be gradually migrated to Debian, for each department to be trained (internally) during the deployment of the new system.
2.3. Why a GNU/Linux Distribution?
BACK TO BASICS Linux or GNU/Linux?
Linux, as you already know, is only a kernel. The expressions, “Linux distribution” and “Linux system” are, thus, incorrect: they are, in reality, distributions or systems based on Linux. These expressions fail to mention the software that always complete this kernel, among with are the programs developed by the GNU Project. Dr. Richard Stallman, founder of this project, insists that the expression “GNU/Linux” be systematically used, in order to better recognize the important contributions made by the GNU Project and the principles of freedom upon which they are founded.
Debian has chosen to follow this recommendation, and, thus, name its distributions accordingly (thus, the latest stable release is Debian GNU/Linux 6.0).
Several factors have dictated this choice. The system administrator, who was familiar with this distribution, ensured it was listed among the candidates for the computer system overhaul. Difficult economic conditions and ferocious competition have limited the budget for this operation, despite its critical importance for the future of the company. This is why Open Source solutions were swiftly chosen: several recent studies indicate they are less expensive than proprietary solutions, despite quality of service that is equal or better, so long as personnel qualified to run them are available.
IN PRACTICE Total cost of ownership (TCO)
The Total Cost of Ownership is the total of all money expended for the possession or acquisition of an item, in this case referring to the operating system. This price includes any possible license, costs for training personnel to work with the new software, replacement of machines that are too slow, additional repairs, etc. Everything arising directly from the initial choice is taken into account.
This TCO, which varies according to the criteria chosen in the assessment thereof, is rarely significant, in itself. However, it is very interesting to compare the TCO calculated according to the same rules. This assessment table is, thus, of paramount importance, and it is easy to manipulate it in order to draw a predefined conclusion. Thus, the TCO for a single machine doesn't make sense, since the cost of an administrator is also reflected in the total number of machines they manage, a number which obviously depend on the operating system and tools proposed.
Among free operating systems, the IT department looked at the free BSD systems (OpenBSD, FreeBSD, and NetBSD), GNU Hurd, and Linux distributions. GNU Hurd, which has not yet released a stable version, was immediately rejected. The choice is simpler between BSD and Linux. The former have many merits, especially on servers. Pragmatism indicates, however, the choice of a Linux system since, its installed base and popularity are both very significant and have numerous positive consequences. Consequent to this popularity, it is easier to find qualified personnel to administer Linux machines than technicians experienced with BSD. Furthermore, Linux adapts to newer hardware faster than BSD (although they are often neck and neck in this race). Finally, Linux distributions are often more adapted to user-friendly graphical user interfaces, indispensable for beginners during migration of all office machines to a new system.
ALTERNATIVE Debian GNU/kFreeBSD
Since Debian Squeeze, it is possible to use Debian with a FreeBSD kernel on 32 and 64 bit computers; this is what the architectures, kfreebsd-i386 and kfreebsd-amd64 mean. While these architectures are labeled “experimental” (Technology Preview), already 70 to 80% of software packaged by Debian is available for them.
These architectures may be an appropriate choice for Falcot Corp administrators, especially for a firewall (the kernel supports three different firewalls: IPF, IPFW, PF) or for a NAS (network attached storage system, for which the ZFS filesystem has been tested and approved).
2.4. Why the Debian Distribution?
Once Linux has been endorsed, a more specific option must be chosen. Again, the criteria to consider abound. The distribution chosen must be able to operate for several years, since the migration from one to another would entail additional costs (although less than if the migration were between two totally different operating systems, such as Windows or Mac OS).
Sustainability is, thus, essential, and it must guarantee regular updates and security patches over several years. The timing of updates is also significant, since, with so many machines to manage, Falcot Corp can not handle this complex operation too frequently. The IT department, therefore, insists on running the latest stable version of the distribution, benefiting from the best technical assistance, and guaranteed security patches. In effect, security updates are generally only guaranteed for a limited duration on older versions of a distribution.