Linux Distributions Compared

The first commercial distribution to adopt an upgradable packaging scheme, Red Hat's 2.1 release includes a single-command upgrade facility. A single script was included to do the upgrade from Red Hat 2.0 or 2.0Beta to 2.1, and it worked very well. At the end of the upgrade, it notifies the user which configuration files have been changed and the names of the files where the originals have been saved.

Unfortunately, going from version 2.0 to 2.1, it replaced the /etc/passwd and /etc/group files (among others) with new ones that had new administrative users, but didn't include any users that had been added to the system since the original install of Red Hat 2.0. No tool was provided to merge the old and new password files, either. Fortunately, Red Hat considers this a bug and will fix it in future releases. It is also fortunate that the previous versions were preserved—Red Hat's RPM tool always makes a backup when changing configuration files—and the upgrade script warned about the change, making it a simple matter to move the original versions back into place.

With this small, easily-fixed exception, the Red Hat upgrade process ran smoothly and took only a few minutes to upgrade a rather fully configured system to the latest version of Red Hat with proper configuration files in place. Red Hat has plans to improve the upgrading process so that it is even smoother for more people; in nearly all cases in the future, a single command should be entirely sufficient.

In general, Red Hat provides a reasonably wide range of applications on multiple architectures. In December 1995, at DECUS/San Francisco, Red Hat announced Red Hat Linux for Alpha, which runs on several different Digital Alpha systems. Red Hat's packaging scheme is designed to support multiple architectures transparently, including building packages, and Red Hat has announced that they are considering other architectures as well.

Red Hat includes a graphical package management tool, as well as a command-line tool. However, their assumption is that people who don't want or need to edit configuration files directly will configure and use X, and their configuration tools are almost entirely X-based.

Red Hat provides your choice of graphical and text-based installations, and can install from CD-ROM, NFS, floppy, or FTP. The floppy and FTP installations only work in text-based mode at the moment. The installation asks as many questions as necessary immediately and then installs all the applications, not requiring user interaction again until after all the packages have been installed.

Red Hat provides their own easy-to-use X configuration program called the Xconfigurator. It uses dialog boxes that ask fairly easy questions to write an XF86Config file to configure X.

The URL for Red Hat's home page is www.redhat.com.

This veteran descendent of the original Linux distribution, SLS, is still easy to install, if you don't mind tending it while it asks questions. It has wide support for installation from different media—it even has experimental support for installing from tape drives—and it still has the best support for installing from floppies. It also has a very wide selection of available software. If you want to use TeX to typeset Klingon or Tengwar, it's built in; just make the right selections while installing. Slackware has a long history and has a rich assortment of packages. Most of the 1000-page tomes covering Linux which are available in any bookstore cover Slackware, so it is also well-documented.

However, Slackware has no real upgradability. To upgrade a package (which is simply a .tar.gz file), you can only remove the old package and install the new one. For a technically advanced user who remembers all the configuration files for the package, who knows exactly what files to back up before doing an upgrade process, and has time to do so, that works, except when the user makes mistakes.

Slackware uses the standard XFree86 xf86config program to configure X, which is not particularly user-friendly, though very thorough. Once you get X running, however, you can take advantage of Slackware's fairly wide variety of X applications.

If you don't mind re-installing regularly to upgrade and demand very fine-grained control over exactly which files get installed, Slackware provides some of the most precise controls over what gets installed and what does not. For instance, if hard drive space is limited, and you want to install only the TeX fonts you want, most of them are selected separately. Thai fonts, OCR fonts, and Gothic German fonts are perhaps not likely to be used by the same people; Slackware allows you to select each of those families (and many more) separately. If you want as many packages as possible provided with the distribution, you will appreciate Slackware's wide range of available software. We counted 326 packages in Slackware 3.0.

Slackware's Web site is at www.cdrom.com/titles/slackware.html.