by Steve Patient

Server Operating Systems

Has Linux hit the big time as a Web server OS? The answer is yes, it has. Major players like IBM are trying to incorporate Linux rather than reject it. Even Microsoft is keeping more than a watchful eye. And the growth of Linux shows no sign of slowing down. Here's why:
January 17, 2000

With Microsoft so vocal it's easy to forget IBM sells nearly as much software - aimed at servers rather than desktops. This made IBM's LinuxWorld announcements in San Jose, California, important. IBM showed the Netfinity 3500 M10, a Linux server with support for dual 100%MHz Pentium III processors at just $1800.

IBM has RS/100%0 boxes running Linux. It shipped a Linux version of its RAID driver, the DB2 database and WebSphere application server. These are ServerProven for Linux, which means they've been optimized for IBM servers. IBM had already ported Linux to its 390 mainframes.

Gerstner has turned IBM around. If he's putting the company behind Linux it's because he expects it to succeed. And it doesn't stop there. IBM is forming a partnership with SAP AG to port the R/3 ERP application to Linux. This is non-trivial application software being ported by two of the world's most successful software companies to a free server operating system.

Everybody's Doing It

The same story is happening all over. Commercial Unix vendors such as SGI and HP are putting Linux on their server hardware. They're not doing it because they want to cut their profits but because their customers are demanding it.

When Microsoft began advertising for Linux gurus you knew it wasn't because it plans to abandon NT, but because it's worried about Linux cutting into its NT Server sales and it's looking for loopholes.

Linux' increasing popularity isn't being driven by traditional commercial marketing efforts. It's a genuine consumer-led phenomenon where those using it extol its virtues to others.

Despite the best efforts of commercial operating system vendors to nay-say Linux - a free, collaboratively built and maintained OS owned by no one - it's the only operating system other than Windows currently expanding its user base. It's already the second most popular Unix-type server OS after Sun's Solaris.

The questions you need to be asking are: why are individuals and companies choosing Linux as a server platform and should you be evaluating it yourself?

So What is This Linux?

Technically, Linux refers to the OS kernel, originally written by Linus Torvalds and maintained by Alan Cox. A complete Linux distribution is built mostly of Gnu Software Foundation applications, so Linux is more properly called Gnu/Linux.

Its major attraction for server administrators, apart from zero cost of aquisition and no seat licence fees, is Open Source; The GPL, Gnu Public Licence - under which Linux is released - requires the source code to be available to anyone. There are no secrets, and no hidden vices in Open Source software.

You probably already know that Apache runs more than 50 per cent of all Internet Web sites. It ships as part of all Linux distributions. You also probably know that versions of Apache run on most server OS's including NT because anyone can port it to any platform.

The average Linux distro contains more than 500 applications distributed under the GPL. Along with Apache you'll find server support for FTP, Telnet, Finger, Email (SMTP, POP3 and IMAP), IRC, newsgroups, NIS, NFS, BIND (DNS), WINS (Via Samba), network printing and lots more.

On the network protocol side you get support for TCP/IP. IPX. SMB (Via Samba again), BOOTP, RIP, PPP, SLIP and most other protocols used anywhere on networks. Linux supports routing, LDAP, dozens of filesystems and now, courtesy of SGI, even filesystem journaling.

You also get a complete suite of network administration tools, compilers, debuggers, Open Source libraries, security tools and so on.

Samba, mentioned above, is amazing. It supports SMB and Windows protocols so effectively it can and does act as a Domain Server for Windows networks - complete with support for encrypted passwords. Linux is the ideal tool for integrating disparate OS platforms into a cohesive network - or just installing instead of an expensive NT box.

And remember, most of the services which come free with Gnu/Linux cost thousands of dollars from Microsoft and other commercial vendors.

Most of an Iceberg is Hidden

For all these reasons a surprising number of network administrators are coming out of the closet and admitting they've been running Linux as a server on Windows networks for years - it's just their managers who didn't know.

They do it because Linux is free, reliable, robust, complete and efficient. Linux was originally designed for PC's running i386 chips. An obsolete PII 166 makes a great Linux based Web server. Because it's Open Source you aren't tied in to the PC platform either. Linux runs on everything from mainframes to Palm Pilots. It even runs on Macs.

In theory, Linux supports SMP up to 16 processors, though 'out of the box' it's optimised for four processor machines. Interestingly, NT also runs best on four processor systems. Linux is already available in 64-bit versions - NT isn't.

Unlike the monolithic Windows, Linux is highly modular. You can strip it right down to the kernel, itself modular, and instal just the parts you want. What server administrators find most enticing, though, is the reliability it offers.

Linux is extremely robust. The kernel contributors regard a crash as a personal failure. It isn't easy to crash it these days. But the best part is you almost never have to reboot Linux. Change anything on an NT box from an application to a modem and you have to reboot.

You can change anything on a Linux box - hardware or software - without rebooting. Astonishingly, it's even possible to change the kernel on the fly. If your company's print servers have been running for years with no down time suspect a techie has sneaked in a Linux box.

Designed for the Job

Linux was designed as a server operating system from scratch. Windows was designed as a single user desktop OS - and it shows.

Linux has one filesystem based on root (/) regardless of how many drives or partitions there are on the machine. No C: and D: drives or software confusion about where it lives.

Linux drives have mount points, which can be anywhere in the file hierarchy. Changing an NT drive layout is a nightmare for users and administrators. No one even knows you've done it under Linux. No hassle and no downtime. You can even extend one Linux filesystem across multiple machines without breaking stride.

NT doesn't support quotas (OK, real soon now). A user can kill your NT server by filling the hard drive. Linux has always supported them. Under NT applications which want to make use of the server must be written in two parts as client/server apps. Linux enables a logged in user with suitable permissions to run apps directly on the server.

Linux' GUI is based on X, which is itself a server. You can use an X app running on the server from any other networked machine. Similarly, it supports font servers - instal once use anywhere.

Server administration largely consists of repetitive actions and monitoring for events. Linux' combination of Perl (or Python or several other scripting languages) with the Cron daemon enables a level of automation almost impossible to achieve on NT.

So Why isn't Linux Everywhere?

Nothing, you're saying, can be this good. Well industry pundit IDC disagrees with you. It says Linux will be the fastest growing server and desktop OS over the next five years. But there are always downsides.

NT is a point and click environment. It doesn't need a guru to make it work, just the ability to read and move a mouse. NT enables companies to employ less skilled server administrators. Linux requires more technical savvy from its administrators.

Company lawyers like to point out the lack of anyone to sue if a Linux system or application lets the company down. Of course, this is a largely a US issue. But it raises a valid point.

It's possible to set up an NT server almost entirely with Microsoft software, or a Sun server with Sun software. Any Linux system will include software maintained by hundreds of volunteer groups, each of which will have a changing composition, agenda, timescale and attitude.

Despite the acknowledged speed of response of the Linux community many managers are as unhappy with the idea of a distributed volunteer development community as they are with a distributed workforce. Managers tend to like centralisation.

Support is Not an Issue

A lack of vendor technical support is the usual managerial reason given for not considering Linux. When did Microsoft last fix a bug for you? IBM, HP, Dell and others selling preinstalled Linux boxes do provide support for their systems.

IBM provides third party support as well as supporting its own boxes. Linuxcare has been set up entirely to provide support while all the major Linux distributors earn a living by providing support. If you need it.

In 1999 Infoworld magazine awarded 'Best Technical Support' to the whole Linux community. It might seem odd to rely on newsgroups and mailing lists but you'll often get the information you need in just a few minutes.

Linux nay-sayers and Microsoft supporters like to point at the lack of a 'standard' Linux distribution. This shows some nerve. Currently in use are Windows 3.1, 3.11, 95, 98, 98se, NT3.51 and NT4 - ignoring service pack levels. You can now add various flavours of Win2000 to the list.

Yes, there are several major Linux distributions ranging from the 100 per cent Open Source Debian, though Caldera, Redhat, Suse, Mandrake, Corel and Slackware but all are built on the same Linux kernel, run the same server software, use the same utilities and so on. The differences are in choice of packages and configuration details for the target market.

It's Pretty, Too

Naturally, a server doesn't really need a GUI, but a GUI does make life easier. All Linux distributions (and most Unix) use X as the graphics server and a window manager on top. There are a lot of wms because, while commercial companies are concerned with brand and image Linux programmers are concerned with cool.

However, while early window managers couldn't begin to compare with the elegance, features, standardisation and usability of Mac OS or Windows this is no longer true.

The KDE and Gnome Integrated Desktop Environments are standard now and they compare extremely favourably with MacOS and Windows. In many ways, because non-commercial software doesn't have to carry baggage, KDE and Gnome have been able to improve on commercial GUIs.

The Bottom Line

While commercial Unix software is generally available for Linux, some commercial desktop software vendors are reluctant to port their products to Linux. It's hard to compete with free.

For example, Metrowerks ported its excellent Integrated Development Environment, CodeWarrior, to Linux (it costs Euro102 from Suse) but since Motorola bought Metrowerks the Pro version has been put on hold.

It can also be tricky to hold on to Linux gurus. Coming from a somewhat anarchistic development culture they won't necessarily share your commercial values. They can be surprisingly reluctant to work for mere money or on projects they don't believe in. You have to woo them.

The only way to know if Linux is for you, though, is to suck it and see. You can buy a preconfigured server from the likes of Dell, QLITech, IBM, Netwinder, Telenet System Solutions, 800Linux.com, Hewlett Packard, Sun....or just instal it on a spare PC. It won't cost you a thing.

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Steve Patient has covered computing, telecommunications, networks and the social and business changes they bring, since 1978. He believes the best a technology writer can hope for is to emulate the monks of the middle ages. To chronicle a small piece of a much larger picture as accurately as possible. It will be down to some future scribe to make these days look like an inevitably unfolding tale.