Timothy Parker Consulting Incorporated

UNIX and its kin: UNIX and Linux comparo

When you are looking for alternatives to Windows, there are only a few.  There’s OS/2, which has a devoted (almost fanatical) following, yet almost no market share.  You can’t even buy OS/2 in a store any more.  And then there’s UNIX in all its flavors: SCO OpenServer, SCO UnixWare, BSDI UNIX, FreeBSD (BSDI), and Linux.  There are others, too, but these are the main choices for Intel-based systems.  Naturally, since we’re a SCO-oriented magazine, we concentrate on OpenServer and UnixWare as the operating systems of choice, but the popularity of Linux has raised several questions about alternatives.  Thus was born this roundup: a head-to-head comparison of UNIX and UNIX-like operating systems.

You probably know OpenServer and UnixWare quite well.  If you are not running them, you’ve read about them in these pages.  So, we will concentrate first on the alternatives.  We’ll look at BSDI, FreeBSD and then several Linux versions, comparing them for their ease of use, installation and administration, stability, and support.  Then, we’ll look at how FreeBSD and Linux compare to OpenServer and UnixWare.  We’re not looking for the “best” UNIX operating system: there is no such thing.  We are trying to find the strengths and weaknesses of each, though, so you can see how your needs can best be met.

BSDI

BSDI is one of the original UNIX variants, now handled through Berkeley Software Design in Colorado Springs, CO.  BSDI UNIX is a full-blown commercial product, unlike the FreeBSD version examined next.  Reflecting its price tag and reputation, BSDI comes in a package containing three CD-ROMs (two for the BSDI Internet Super Server product and one for contributed source code).  BSDI is intended as a server product, although it will function quite happily as a workstation.  The BSDI package also contains a spiral-bound book containing installation and release notes.

The documentation accompanying BSDI is full of details, but rather poorly laid out.  There’s no overview of the installation process, or of the product as a whole.  UNIX experience is taken for granted.  Experienced UNIX users will be able to find what they want, although newcomers will be frustrated.  The installation process is not for newcomers, either, requiring interaction from the installer.  A good knowledge of UNIX certainly helps with some of the installation queries.  To help ease the installation, and express installation option is available but the default settings will not suit most server setups. Configuration of peripherals again requires some knowledge of UNIX, and is not for beginners.

The strong heritage of BSDI UNIX shows in the stability of the final product, as well as the product’s suitability as a server. The entire operating system suits its role as a server of practically any UNIX-supported service.  During our testing the server behaved perfectly, not causing any crashes or requiring any reboots.  Technical support is provided as part of the package for 60 days, after that requiring support contracts.  For its role as a commercial server, BSDI is an excellent tool.  It is less suited to use as a workstation.

FreeBSD

BSD’s UNIX is the original, free operating system with UNIX roots.  With all the fuss about Linux, FreeBSD tends to be a little overlooked.  Unlike Linux, which is really a UNIX workalike, FreeBSD is really UNIX.  On top of that, like the name implies, FreeBSD is really free (although you might get hit with media charges).  So why isn’t FreeBSD sweeping the country instead of Linux?  There are a number of issues with FreeBSD, all of which detract from its acceptance.  The first problem is installation and configuration routines, the next is lack of support for many common hardware peripherals, and the third is a lack of documentation and technical support.

If you are looking for a trouble-free installation and configuration process, FreeBSD is not going to keep you happy.  The installation procedure is quite complex, with lots of interaction expected from users.  Configuring hardware and peripherals is a step-by-step, one device at a time process with no real automatic detection routines.  Drivers for the most common IDE and SCSI devices are available, but if you have more esoteric devices, you may be out of luck.  For example, we couldn’t get a CD-RW to work properly other than as a read-only box, our Jaz and ZIP drives were colorful paperweights, and drivers for multiport serial cards didn’t work.  In many ways, FreeBSD is a hacker’s dream.  If you don’t understand the internals of a UNIX kernel and know C or C++ inside out, though, you will have problems with FreeBSD unless you have a vanilla setup.

Documentation is usually supplied on-disk or off a Web page or FTP server.  For the most part, it resembles the early Linux documentation: written by programmers for programmers.  There are few developers who can write engaging documentation for beginners, and this is especially true in the FreeBSD field.  Trying to find sources of information can be frustrating, even on the newsgroups.  There are a bunch of talented people who try to help through Usenet, and there are good FAQs and Web sites devoted to FreeBSD, but this operating system can’t really be used by anyone who’s not a system administrator, has lots of patience, and doesn’t need special device support.

Once you get through the installation and configuration procedures, though, FreeBSD has one really important asset: it is bulletproof.  While our Linux test machines would occasionally hang up, FreeBSD was rock solid.  Hardware requirements are benign: a low end 80486 with 8MB RAM is enough to run a solid, reasonable system.  On a Pentium with lots of RAM, FreeBSD runs smoothly with no paging even under loads that slowed Linux down a little.  As a server, FreeBSD offers all the daemons you could wish for.  It makes a better server than Linux, as long as you can get support for all your devices.  As a workstation or client machine, though, Linux is a better choice.

A plethora of Linux

There are over a dozen distributions of Linux available, all mostly slight variations of each other.  Several have improved installation and configuration routines, several have bundled extra software, and a few offer telephone technical support.  But underneath it all, they all tend to use the same basic Linux kernel and utilities.  There are differences between the major versions of Linux that matter, though. 

To compare the different versions of Linux we installed the five most popular versions (we dropped Mandrake and Slackware Linux from the tests due to technical problems with the distributions), as well as the latest major introduction from Corel, on identical machines.  We took careful note of the installation and configuration process, both from the ease of installation for someone with no technical computer knowledge and from the more advanced point of view of someone who knows what they are doing and wants to configure items the way they wish. We then tried swapping several peripherals among machines and tried configuring and using them on each platform.  We also noted the ease of system administration tasks, including regular routines such as backup and restore cycles, maintaining application servers, setting up and running remote access modem banks, and adding HTML servers.

The test platforms for all these tests were generic Pentium II 350MHz machines with 128MB RAM, 9.1GB SCSI hard drive, SCSI CD-ROM,  3.5-inch floppy, and ATI PCI video cards. We also tested each machine in a straight IDE configuration with 13GB hard drive and 40x IDE CD-ROM. Peripherals we tested on each machine included both internal and external tape drives, scanners, ZIP and Jaz drives, CD-ROM jukebox, CD-RW external drive, and two types of sound cards.  All machines also had a dedicated HP LaserJet 6P printer, and through the TCP/IP network was configured for access to an HP 8100DN laser and HP 4500DN color laser. Networking cards were 3Com 10/100 PCI cards, and each system was configured with static IP addresses.  A gateway was configured for access to the Internet.  Finally, each machine had at least one internal and one external 56kbps modem attached, configured, and tested for access to the Internet. Each machine was left to run 24 hours a day for three weeks straight, performing scripted test routines overnight to try to exercise the system’s I/O routines as much as possible.

The newcomer to the Linux stable is from Corel, famous for their WordPerfect and CorelDraw products.  Corel Linux is Debian Linux at the core, although the Corel-developed installation routine makes this version of Linux the easiest to install and configure of any version we’ve seen. In its simplest form, a single mouse click is all that’s needed to install Linux on most systems! For someone who is not familiar with Linux, or doesn’t want to get involved in nitty-gritty details of a Linux configuration, Corel Linux wins hands-down.  Where the ease of configuration gets in the way is for more advanced tasks such as manually tweaking devices, as well as modifying existing setups.  The documentation included with Corel Linux sets the standard for all other versions.

By default Corel Linux can take over the entire hard drive, or exist in a DOS partition for dual-boot systems.  Either installation is a simple menu choice, with the automatic hardware detection routine taking all the hassles away from users.  The detection process picks up all the usual PCI and AGP devices, although some ISA/EISA cards will cause problems and require manual configuration.  This is especially true for multiport serial cards and driver boards for external peripherals like Bernoulli drives.  The software bundle is a bit of a let-down compared to other versions, with many utilities and add-ons left off.  However, you do get WordPerfect 8 for Linux, which solves the word processor problem once and for all. Suitability as a server is weak, with very little documentation covering the issue.  However, as a workstation or a first-time Linux system, Corel Linux is the best of the bunch.

Caldera OpenLinux 2.3 used to be the king of the Linux heap when it comes to bundling, support, and overall presentation.  Like Corel Linux, Caldera’s offering has an excellent installation routine (called Lizard).  The interface is clean and easy to work with and should provide a trouble-free installation for most machine configurations.  We did run into some trouble with our SCSI configurations, especially when it came to SCSI drivers, although we managed to install with a little configuration tweaking.  If you are adding Caldera OpenLinux to an existing Windows system, the process can be automated for the most part although you do have to pay attention to several prompts. Caldera OpenLinux includes a version of PartitionMagic which helps break up your existing hard drives into new partitions without having to reformat everything.

The software bundle with Caldera OpenLinux is very good, although the server toolset is a little weak.  Technical support is available, but quite expensive. E-mail technical support is free (don’t expect a quick answer), or you can use the telephone at a rather hefty $150 per incident!  The documentation included with Caldera OpenLinux is excellent. As a server, Caldera OpenLinux is good but lacks some important tools such as a secure Web server.  There are better alternatives for dedicated server use, but as a workstation Caldera OpenLinux is on a par with Corel Linux.

SuSe Linux 6.2 has one of the poorer installation and configuration routines among the versions of Linux we tested.  In many cases, it is downright confusing or contradictory, and getting some peripherals to work requires near miracles. The documentation (442 pages!) doesn’t help newcomers as it is full of technical wordage that most newcomers to Linux will not understand.  Veteran Linux users will be able to work through the installation, although even experts will have to puzzle out a few of the prompts and warnings. Once past the installation, though, things look better.  SuSe Linux has a large bundle of software, including most of the user and server tools you will require. That’s not surprising when you count the CDs that come with the complete package: six of them! 

Telephone technical support is limited in time, but is available free in most cases.  After the free period, support is available at reasonable costs.  Where SuSe Linux shines is in the server configuration as practically every server tool you could want is somewhere on the disks.  SuSe Linux is definitely for the experienced Linux user who wants a server setup: newcomers need to look elsewhere.

TurboLinux  versions of Linux are available in three configurations: workstation, server, and cluster server.  As the names imply, workstation is suitable for a non-server standalone or networked role, server is good as a single CPU server, and cluster server is available for networks clusters of servers.  TurboLinux is one of the more expensive versions of Linux available, although the bundles make up for some of the costs.  The workstation version is a reasonable $50 and includes the downloadable version of Corel WordPerfect for Linux.  The version of TurboLinux we tested is the server product, which the company bills as the most secure version of Linux available. A copy of BRU’s backup and restore utility is included in the package.

Installation of TurboLinux was on a par with other Linux versions, although not as slick and easy to use as Corel or RedHat Linux.  Configuration for peripherals is very good, with excellent hardware and software support from the distribution CDs.  RAID levels are supports as part of the server package, which is handy for larger Linux servers.  The cluster server product allows two or more Linux servers to cooperate for load balancing, but we did not test that version.  As a server, TurboLinux offers a good toolset including optimized utilities that seemed faster than other versions of Linux.  The security of the basic installed package was excellent, with many of the known holes in Linux patched for you.  We didn’t assess TurboLinux as a workstation package, but as a server it impressed us mightily. 

RedHat 6.2 is the grand-daddy of the Linux setups as far as most people are concerned.  RedHat is the most well-known (and best capitalized) version of Linux available. There’s a lot to like with RedHat: the installation process is driven through an interface that is easy to understand by most, the bundle is a good size, and a new network-update feature makes upgrading to the latest versions of the software simple.  The latter is unique to RedHat and makes the operating system even more attractive.  Configuration and installation are a little more involved than Corel and Caldera Linux, but not onerous by any means.

The documentation suite is rather poor, badly written and poorly laid out. Providing backup is an very good technical support policy, depending on the version of RedHat you acquire. If there’s a weak point in the RedHat package as far as users are concerned, it’s lack of support for the KDE desktop, which is hardly mentioned.  KDE is far more popular than the GNOME desktop RedHat pushes. As a server package, RedHat wins hands-down.  It has ever server tool and utility we wanted, including secure services, and makes the ideal server Linux.

Debian Linux is really a release from GNU. The strength of Debian Linux is its support software: the utility bundle is stacked with software. The weakness is Debian Linux installation and configuration routines: they almost tie for last place with SuSe. This is definitely not a package for newcomers to Linux. As for documentation, don’t expect anything printed.  There’s no documentation for this release except the usual complement of volunteer-written manuals.

Support for Debian Linux is mostly through the newsgroups and IRC, showing the open source roots of the GNU system.  Toll free support is available for a fee.  As a server Debian Linux fares well as there is almost every piece of software you can ask for on the disks.  Unfortunately, it’s up to you to figure out how to install and configure it.  Debian Linux is really the low-cost alternative for those who want to keep things cheap.  There are better Linux versions for all others.

So which Linux is best for you?  If you don’t need server applications, then Corel Linux is hard to beat.  For newcomers, Corel Linux is the choice without doubt.  For server applications, RedHat or TurboLinux offers the best configuration and support, although you should not be a Linux newcomer if you plan to set up a server. Performance differences between the Linux versions we tested were minimal, since they are all based on the same kernels.  Peripheral support was best with RedHat and TurboLinux, although all versions we tested worked with all our peripherals after a little convincing. TurboLinux behaved the best as a secure server, with better performance and out-of-the-box security than any other.

Linux vs UnixWare and OpenServer

How does Linux stack up against FreeBSD, BSDI UNIX, SCO OpenServer and SCO UnixWare?  There are a few items that stand out for each operating system.  First, there’s the cost issue.  Linux is considerably cheaper than either SCO operating system, and as such is cheaper to deploy as clients and servers.  Also, since Linux has lower hardware requirements, less money must be spent to provide similar performance from the clients.  Linux also offers many Windows-like tools that SCO operating systems lack, as well as smooth integration between Windows filesystems.

On the other hand, there are two important features of both OpenServer and UnixWare that make it more attractive than Linux.  The first is support.  SCO’s technical support services are superior to any offered by a Linux vendor, and although Linux has a large number of people answering questions on Usenet newsgroups and similar vehicles, Linux still lacks the orchestrated, full technical support SCO offers.  For mission or business critical applications, technical support is important.  Support also extends to drivers for new peripherals and older devices.  While the influx of new programming blood into Linux is helping Linux be the first with support for many new technologies, there is a huge backlog of peripherals that SCO supports that Linux can’t. 

The second important aspect of SCO’s operating systems is robustness and suitability as a server.  While several versions of Linux are good server platforms, the simple fact is that UnixWare 7.1 will outperform Linux on equivalent platforms.  Both UnixWare and OpenServer scale across platforms better than Linux, too.  While there are multiprocessor versions of Linux available, they are not as efficient and robust as either SCO operating system.  Linux aficionados often quote figures that Linux servers account for many of the Web servers in use, but this doesn’t consider the fact that most of these servers are small, single processor, low-hit devices that don’t require a fast, scalable, operating system.  If a secure, fast, reliable Web server is necessary, either UnixWare or OpenServer will outperform a Linux system.  The core of both SCO operating systems is Unix, of course, and it has been around for thirty years of development, debugging, and enhancements.  Linux is a relative newcomer of only a few years.

System administration tasks are an interesting contrast on these platforms.  There are many similarities between Linux and SCO operating systems, although the latter have the more flexible and versatile tools.  There are many companies now porting to Linux, but they are still catching up to the toolset available to SCO administrators.  Enterprise-wide tools are not available for Linux, yet, either, and many client-server applications are not ported.  Simple tasks like tape backup and restore cycles are much easier with SCO operating systems, thanks to the backup tools available like Cactus’ Lone-Tar and MicroLite’s BackupEdge. As for RDBMSs, 4GLs, and enterprise tools, many will never be ported to Linux while they are currently available for either OpenServer or UnixWare.

End users are less picky about their client machines, as long as the result is access to the applications the users require.  For client machines accessing servers, the choice between Linux, SCO operating systems, or Windows is more a matter of support and policy than one being better than the other.  All these operating systems can act as X clients to a UNIX server, all can network efficiently, and all have GUIs that hide the operating system from the user.  Documentation for the end user may be an issue in some cases, which tends to favor Windows and SCO platforms.

Operating system robustness cannot be underestimated for either users or administrators.  There are few things more annoying than system crashes, especially in a work environment. In our tests of these operating systems, all but one of the Linux systems suffered two or more crashes during the testing period.  The BSDI, FreeBSD system and both SCO operating systems suffered no crashes at all.  While end users are usually willing to tolerate a few occasional lockups and crashes of their client systems, few will tolerate server crashes and the subsequent lack of services.

Should you consider replacing UnixWare, OpenServer, or Windows clients with Linux clients?  By all means, as long as you realize the limitations and strengths of Linux.  Linux is a remarkable operating system and will serve many client machines well.  Replacing servers and high-end workstations with Linux is another matter, though.  Since few commercial organizations are willing to risk crashes or lack of technical support, it is likely that SCO operating systems will still remain the OS of choice for these platforms, especially for the larger platforms. 

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Last modified: January 23, 2007