SCO Linux 4

SCO Linux 4 provides the bare bones of a high-availability clustering solution.

SCO Linux 4 is a server operating system intended for the same market segment as Red Hat Enterprise Linux. SCO Linux is based on UnitedLinux, a common base Linux distribution put together by four companies: SCO Group, SuSE, Conectiva and Turbolinux.

UnitedLinux has embraced all the major Linux standards, including the filesystem hierarchy standard (FHS), Linux standard base (LSB) and Open18N internationalization. On top of this stable foundation, each partner in UnitedLinux can ship extra features or customizations. For the most part, though, it should be easy to move from one version of UnitedLinux to another.

UnitedLinux clearly is intended to run on servers rather than on workstations. It uses the Linux 2.4.19 kernel with the O(1) scheduler patch applied, and it has server features enabled, including large memory, IPv6, logical volume management (LVM) and enterprise volume management system (EVMS).

Although UnitedLinux supports the major server architectures—x86, IA-64 or Itanium, AMD's x86-64 and IBM's zSeries, iSeries and pSeries—SCO Linux 4 currently supports only IA-32. SCO has promised IA-4 support in the near future. SuSE Linux Enterprise Server 8, also based on UnitedLinux, offers x86, IA-64 and IBM zSeries, iSeries and pSeries support.


SCO Linux 4 is distributed on three CDs. The first is the installer CD, and it also contains SCO-specific packages to install. The other two CDs are the standard CDs for UnitedLinux 1.0. They provide the common core of UnitedLinux, and any Linux distribution based on UnitedLinux 1.0 includes them.

The installer is a rebadged YaST2 installer from SuSE. It correctly detected most of the hardware in my test system and set it up with sensible defaults. It partitioned my disk and set up ReiserFS on the main partition.

Figure 1. YaST2 installer, rebadged for UnitedLinux. The SuSE lizard remains.

For the most part, the installer worked well and the installation went smoothly. There were a few rough edges, but nothing an experienced Linux user will have trouble handling. For example, when I tried the GNOME desktop, I received an error message because the hostname wasn't in /etc/hosts. When I tried the KDE desktop, an error message from the sound server came up because the driver module for the sound card was not loaded. Someone new to Linux probably will need to contact SCO support to sort out a few things.

The packages available for installation are mostly server-oriented. It is possible to install packages from SuSE if something you want is missing. To test this, I installed the SuSE 8.0 package for Stella, an emulator for the Atari 2600 game system. It worked perfectly, and now I can play old Atari games on my enterprise server.


It's possible to configure a SCO Linux 4 system using SuSE's YaST2, either character-based or GUI, but the recommended and supported way is to use Webmin. Webmin is a web-based front end for system administration that makes many tasks as easy as clicking buttons on a web page. Also included is Webmin's companion system, Usermin, a similar system that lets users configure their own accounts. Webmin and Usermin can be run locally or from any computer that can access the web server on the SCO Linux 4 system.

Many services are included, but few are enabled by default. Using Webmin, it's easy to start up only the services you need or set them to start up on particular init levels.


When you log in with KDE 3, you see a nice desktop, ready to go. Icons are set on your desktop for Webmin and Usermin, and the KDE panel has a selection of useful program launchers.

Figure 2. The KDE desktop, with a Webmin session in Konqueror.

Not so on the GNOME 2 desktop; it is barren, with few launchers to be found. UnitedLinux includes only the minimum core of GNOME 2.0—even GNOME Terminal is missing. The GNOME 2 support includes everything you need to run GNOME 2 applications under KDE or to launch KDE applications from the GNOME desktop. But if you actually want to work in the GNOME 2 environment, plan on spending some extra time installing missing pieces of GNOME and setting up a usable desktop.

DocView is a slick web interface that uses ht://Dig to put all the system documentation at your fingertips. You get man pages, GNU info pages, HOWTOs, Perl documentation and KDE documentation, all nicely browseable and searchable. GNOME, Python and other subjects are searchable but not included in the table of contents for browsing. To add them you would need to edit DocView files in /usr/lib or set up your own documentation pages.

Figure 3. DocView, a Slick Web Browser Interface to Documentation

Basic development tools are included, and they are up to date. GCC/g++ 3.2, Python 2.2.1, Perl 5.8.0 and gdb 5.2.1 are all included, but integrated development environments, such as KDevelop, Anjuta or IDLE, are not. However, Glade 1.1.1 for GNOME 2.x is included.