Choosing a Linux Distribution

1. Priorities

There is often a tension between these priorities. Stability and the availability of the latest versions of software, for example, are in tension because the latest versions of software are rapidly changing, have been tested less, and are perhaps less stable. Larger deployments to the desktops of computing novices or enterprise-wide critical systems will tend to favour stability, whereas deployments to advanced users' desktops or development servers may favour the latest versions.

Often initial deployments of Linux, whether individual or institutional, are experimental deployments, which enable subsequent decisions to be made on a more informed basis. Institutions moving to Linux often move incrementally, starting with expert computer users, then "back office" servers running network connectivity, email, databases, and web servers. As the internal skill-base grows in depth and breadth, it is used in other areas such as kiosk machines and user desktops. The ability of institutions to move incrementally in this manner is built upon open standards: DNS, LDAP, Kerberos, SMTP, IMAP, HTTP, and other standards help different operating systems and applications to co-exist with fewer compatibility issues.

2. Support

Support can be the biggest issue for both individuals and institutions moving to a new software platform. Clearly individuals and institutions need different kinds of support. Individuals considering migrating are typically technically aware and have a higher than average degree of technical competence; they are often willing to attempt to solve a problem by searching the web and trying different alternatives. They are also more likely to be comfortable with IRC chat channels, mailing lists and Linux User Groups (LUGs) which are the primary support mechanisms for non-commercial Linux distros. As with any significant upgrade or ICT change, staff and students with a low level of technical awareness and competence are likely to need extra support. Support can be obtained from a number of sources:

• Self support is when users are expected to "work things out for themselves". For Linux distros this generally means turning initially to the IRC channels, mailing lists and wiki pages which are the first line of support for each distro. In the case of non-commercial distros (Debian, Scientific Linux, Gentoo, etc.) self support is the primary method of support. Self support is normally only an option for technically experienced users.
• In-house support is support from an explicitly resourced group within an institution. Often this is in the form of an internal help desk, or internal documentation on how to use applications widely deployed within an institution. Most institutions provide at least some in-house support already, and in many cases similar kinds of support are required before and after a switch to Linux. In-house support is most effective when a uniform set of software is used across an institution, because this enables support materials and support staff to have a more comprehensive knowledge of the system.
• Peer support is offered by one's peers, that is other users with shared interests. Peer support is offered in the expectation of some form of quid pro quo, usually that the supported party will in turn offer some level of support and experience sharing back to their peers. Peer support can work at the institutional level by institutions sharing information about their experiences, failures, and solutions. Considerable institutional level peer support occurs at events such as the UKERNA Networkshop conferences. Peer support can also work at the individual level. LUGs are specialist forums for individual-level peer support. Peer support is most easily obtained for distros which are already in use by peers (or which peers have identified as targets for migration). Peer support is greatly enhanced if an individual or institution makes similar deployment choices to their peers. Thus, those working in grid computing, which has a strong installed base of Red Hat and the very similar Scientific Linux, are likely to get significantly better peer support if they choose Red Hat or Scientific Linux.
• Commercial support is provided either by independent companies, or those linked to commercial Linux distros (Red Hat, SuSE, Mandriva, etc). Many of these companies provide a variety of support packages with combinations of group training sessions, on-site technical support, email support, telephone support, and even fully managed desktops. Training materials and technical support scales very effectively as the number of people requiring support increases. For this reason commercial support is significantly cheaper if a distro is selected which already has a strong following.

The individual circumstances and culture of each institution will largely determine what mix of support it offers teachers, learners, and researchers.

3. Distributions

Each distro reflects a different community; a different set of priorities and a different set of resources bought to meet those priorities. A comprehensive list of distributions can be found on DistroWatch.

Commercial distros have the backing of a specific company, which enables them to focus resources in ways non-commercial distros cannot. Commercial distros are good at producing polished installers, consistent desktop user interfaces, and integrated support packages. All the major commercial distros have free versions (for example, Red Hat has Fedora and SuSe has OpenSuSe). These free versions typically offer a similar (or identical) set of features but lack official support and certification.

Non-commercial distros are backed by a community rather than a company, where users are encouraged to give feedback and help with documentation, bug reporting and so-forth. Non-commercial distros are typically chosen for deep customisation because their support and infrastructure systems are still relevant after deep customisation breaks the distros certification system. Without a link to a company, non-commercial distros are shielded from the vagaries of take-overs and changing business plans. Support is primarily peer support through chat, wikis, mailing lists and similar, although many third parties provide commercial support for non-commercial distros.

Particular strengths of individual distros used in higher education include:

Debian:

Offers a very large community of developers with a strong ideological vision. Has a large pool of available packages built around the Linux, BSD, or Solaris kernels. Traditionally hard for new users to install.

Gentoo:

A distro focusing on fine-grained optimisation of installations to particular hardware. Uses a flexible system for selecting which packages are installed and how they are compiled and configured. Full installation and configuration can be lengthy.

Knoppix:

A LiveCD/LiveDVD derivative of Debian. Excellent for resetting forgotten root passwords and recovering from hard-disk crashes because it runs directly off the CD/DVD. Generally unsuitable for day-to-day desktop or server use.

Mandriva (formerly Mandrake Linux):

A commercial distro with a European focus and strength in internationalisation. Easy to install and user-friendly.

Red Hat:

The longest-established commercial distro, widely supported by large hardware and software vendors such as IBM and Oracle. Widely used in grid and scientific computing.

Scientific Linux:

A subscription-free binary-compatible derivative of Red Hat, backed by CERN. Widely used in grid and scientific computing.

SuSE:

A commercial distro from Novell with strength in localisation and on the desktop. Covered by some campus agreements with Novell.

Ubuntu:

A non-commercial derivative of Debian with commercial-style end-user polish and a six month release cycle. Currently the focus of many new installs, especially end-user desktops installs. Easy to install.

All of these distros are either free of charge or have free versions; casual trials and demonstrations are available for download. Despite their differences, all of them have at their heart the Linux kernel and the GNU tool-chain from the FSF, which combine to offer a POSIX environment.

4. Further reading