Since its introduction several years ago, Linux has become one of the most widely used operating systems for PCs. Recent ports to other machines bode well for its popularity spreading, too. It’s not hard to understand why Linux is popular: the price is minimal (free or a small media cost), it’s a full-blown UNIX, and it has widespread support on the Internet.

Linux is in many ways the quintessential hacker project: many programmers contribute their time and effort to improving the basic package, and new products appear for Linux with increasing frequency. The thirst for Linux software and literature has spawned a slew of books with included software, including seven of the author’s own which have been translated to half a dozen languages.

Many UNIX veterans view Linux with distrust, remembering many quasi-complete UNIX ports that came before. Yet Linux has established itself solidly with a wide market, from home PC experimenters to large ISPs and database platforms, all happily running securely under Linux. With backing from larger UNIX manufacturers, products like multi-port cards and remote access servers now work perfectly under Linux. While products like SCO Unix are not threatened by Linux, the popularity of the upstart UNIX version is good for the industry as more users realize the strengths and capabilities of this operating system. If only a few are converted to the better supported commercial versions like SCO, the whole affair can be considered a success.

From the introduction of the operating system, several companies have collected and assembled all available Linux material onto CD-ROMs. Slackware and RedHat are the most popular. Caldera appeared on the Linux scene a while ago, offering more professional assembled and tested Linux collections. With the appearance of these nicely-packaged Linux versions on shelves of national computer superstores and smaller chain stores, Caldera has turned many non-Unix people on to Linux. The company’s growth has been remarkable, and the latest versions of Caldera’s Linux software is a good reason why their success will continue.

Caldera offers two different Linux packages called OpenLinux: Base and Standard. The difference between the two is the software bundled with the basic Linux operating system. Both versions use the same kernel, Linux 2.0.29. The OpenLinux Base package includes the kernel and standard utilities including networking, the latest security patches, the Apache Web server, Netscape Navigator browser, a set of Internet utilities for reading mail and newsgroups, X11R6 (both Metro-X and XFree86), fvmw (a Motif-like window manager), Looking Glass desktop, and a ton of add-ons. For programmers, OpenLinux Base adds a number of languages including the Java Development Kit, C and C++ compilers, Perl, Tcl/Tk, Python, and a suite of program development tools. Rounding out the Base package is a CD-ROM of evaluation software from many different vendors, all available for examination prior to purchase. The OpenLinux Base package used a Caldera-developed installation and configuration utility (as well as a bootable CD-ROM) to simply the task of getting Linux on your machine and working properly, as well as supporting well-written documentation.

OpenLinux Standard adds Netscape’s FastTrack Server, Netscape Navigator Gold, NDS-aware NetWare clients, NDS and Bindery agents, a set of StarOffice office applications (word processor, spreadsheet and presentation graphics software), Adabas-D SQL database Personal Edition, and a few other bits and pieces for users. The two versions are aimed at slightly different users: the Base package is ideal for programmers and knowledgeable hackers, while the Standard package is a one-stop Web server and operating system environment.

Caldera’s support for Linux goes one step further, adding Wabi 2.2 for OpenLinux. Wabi (Windows Application Binary Interface) lets Windows software run under Linux’ X desktop. Most Windows well-behaved applications (which rules out many games) work perfectly well under Wabi.

To test Caldera’s versions of Linux, we lined up two 166Mhz Pentium Pro machines with 64MB RAM each. One was equipped with EIDE hard drive and CD-ROM, the other with standard SCSI hard drive and CD-ROM. Both used an ATI Mach64 video card, and an SMC network card. We installed OpenLinux Base on the EIDE machine and OpenLinux Standard on the SCSI machine. Both versions of OpenLinux require a minimum of 250MB free disk space, although more is recommended. (You can install a Linux system in as little as 40MB, but that won’t include X, and user or program development tools.)

Two partitions are required, one for the data and the other for a swap space. Both partitions can be created automatically by the Linux installation routine, but if you are installing on a machine that already has Windows or another operating system on it, you should adjust disk partitions for that operating system first to prevent overwriting data. An included utility called FIPS can adjust partitions without reformatting the entire disk, but you should make a backup of existing software just in case. Commercial products that alter partitions dynamically can also be used to free up disk space. OpenLinux can coexist with any other operating system on a hard disk, although only one can be active at a time (of course). OpenLinux can address Windows and DOS partitions for files, which could be handy for some.

To install Linux, two floppy images must be copied from the CD-ROM. Two high-density diskettes are required, one for the boot and one for the root images (much like SCO UNIX). The Caldera installation routine will guide you through selecting the proper images, and copy the data to the diskettes. You can do the procedure manually, but why bother? After creating the boot and root diskettes and setting up the Linux swap and data partitions, a reboot from the floppy starts the entire installation process. Menu prompts guide you through the process and require little attention. A full installation can take a couple of hours. We were suitably impressed with the installation routine, especially after working with some pretty atrocious configuration utilities in earlier Linux versions.

After installation is complete, networking must be set up and verified, and some tweaking may be necessary for your system to display X and fvmw, then the system boots cleanly. Once running, OpenLinux Standard and Base behave very much like any Unix version. Linux is a mix of BSD and System V, so users who only know SCO Unix may have a bit of a task finding files and directories. Other than a change in directory locations, OpenLinux behaves very much like SCO Unix and UnixWare.

To test the performance of Caldera’s OpenLinux Base, we used a Fast Ethernet network to load up X sessions from twelve Windows 95 PCs running WRQ’s Reflection X Suite. The twelve Windows 95 machines each connected to the OpenLinux Base package through TCP/IP and launched X sessions with four windows running scripts to load the server processor. To add to the load, we launched an FTP session on each machine that read a 100MB database file from the server, then wrote it back to the server in a continual loop. To test performance, we used the standard timing utilities provided by Linux, as well as a stopwatch to measure time of completion for a number of involved server tasks (including a SQL database reindex, database lookup, shell script execution, and Usenet newsgroup reads).

We then repeated the same tasks on our SCO OpenServer 5.0.4 server which has the same processor and RAM complement, differing only in that it uses a SCSI interface instead of EIDE. Even with the speed advantage of SCSI over EIDE, the OpenLinux system measured an average of 15% faster than OpenServer when heavily loaded. When we eased the client load to two Windows 95 machines, performance was almost even.

Setting up a Web server with OpenLinux Standard required the same set of steps as SCO’s Internet FastStart using the same Netscape software. We copied our in-house network Web configuration to the OpenLinux Standard server from our SCO FastStart server, and performed a sustained load test on that platform against the OpenServer FastStart server. The results were closer under heavy load, with OpenLinux measuring an average 7% faster than the OpenServer machine. With light loads, the two servers measured almost the same. Both could handle approximately the same number of queries at once.

If there is a problem with Linux, it is security. Much has been made of several well-known security holes in early Linux kernels. Several small ISPs who used Linux as their server found out how easy it was to break into and corrupt early kernels. Many patches and a few major releases later, all the standard security holes are covered. We used our standard security tests on the OpenLinux systems and found them to be well protected. OpenLinux doesn’t offer a security level as high as SCO’s UnixWare and OpenServer C2 levels, which may be an issue for many companies that do business on the Web, but for many people Linux is more than secure enough. A let’s face it, if you run a mega-buck corporation that needs high-level online security or information transactions, you really should be buying a commercial product like SCO anyway.

After playing around with the Standard and Base releases of OpenLinux for a week, we decided to try Caldera’s Wabi for OpenLinux. As already mentioned, Wabi allows most well-behaved Windows 3.X (not Windows 95) applications to run under X, although there is a performance hit. Wabi and SCO Merge do the same tasks, and have the same performance degradation, under SCO OpenServer and UnixWare. Installing Wabi is simple from a CD-ROM, and it can be installed in about fifteen minutes. You must have your own copy of Windows 3.1, 3.11, or Windows for Workgroups, as it is not included with the Wabi package. Wabi for OpenLinux requires 10MB disk space. A minimum of 16MB RAM is required to run Wabi under OpenLinux, but more is highly recommended. On our systems with 64MB RAM we had no delays while RAM was paged.

We tested Wabi for OpenLinux with several applications. Basic office packages like the suites from Corel, Microsoft and Lotus worked perfectly, although we did get the occasional video artifact (often showing up as windows not being closed properly or color map corruption). These usually cleared with a minimize and maximize sequence. No 32-bit applications work under Wabi for OpenLinux, so any Windows 95 or Windows NT specific applications (such as the latest versions of Word and similar tools) won’t run at all. Networking and access to serial ports for modems worked flawlessly with the packages we tried, including Delrina WinFax. We did run into problems, as expected, with games and some TSRs. Games especially are a problem as they tend to address devices directly, which Wabi won’t allow. In most cases, these resulted in a locked window that could be killed from an X term. In a couple of cases we had to reboot the machine to clear the problem.

Performance under Wabi for OpenLinux is about 40% slower than on a native Windows machine. Since most people will use Wabi for basic applications like work processors, this performance hit will be negligible except for program load and some save operations.

For the average user, is Caldera OpenLinux a reasonable alternative to SCO operating systems? The answer depends on what you want to use the system for. If you are interested in playing with a Unix operating system for learning purposes, either system will work well. The advantage has to go to the Caldera systems because of their much lower price. For a workstation on an existing Unix network, the choices get more complicated. We did like OpenLinux a lot, but on a network of SCO-based systems supporting a non-SCO platform would be a problem for an administrator. However, a mixed network of several platforms may not be as much of a hassle. Certainly Caldera OpenLinux works exceptionally well as a workstation attached to a larger Unix server.

For commercial or server use, there are a number of issues that must be factored. First is the cost of the system; Caldera wins there without a problem. Support from vendors of software and hardware is important, and SCO has the edge there (although many vendors are offering Linux drivers for their products). Security is another important issue, and both SCO and OpenLinux offer very good security, but for higher security installations SCO has the only game in town. For Web server purposes to the Internet, again, the same issues arise. Performance isn’t as much a difference as the security is. Caldera OpenLinux definitely offers an interesting and viable alternative to those looking to provide Unix platforms more inexpensively than commercial packages like SCO, and there are not many compromises necessary to justify OpenLinux. While SCO isn’t likely to be worried about losing their market, it is gratifying to see Linux do well. Caldera does Linux very well.