FreeBSD for Web and E-Mail Servers

FreeBSD for Web and E-Mail Servers
“Planning to install your own server? Take a look at FreeBSD.”
by Jack Dunning

Although FreeBSD as an acronym is not heard as often as the word Linux, it certainly deserves serious consideration when someone is about to enter the Unix-compliant world. FreeBSD originated with a group at the University of California, Berkeley—hence, BSD (Berkeley Software Distribution). It differs from Linux in that it is a complete operating system, whereas the various flavors of Linux are built around a standard controlled kernel. For the user this is a technical difference, since once installed, both FreeBSD and the different versions of Linux will run almost all the same software without change. Plus, to further blur the lines, FreeBSD has also spawned other, similar operating systems such as OpenBSD and NetBSD. Even Apple's OS X is based upon FreeBSD.

The wide use of FreeBSD is no fluke. It is widely accepted as one of the most stable and reliable operating systems available. Many of the big Web sites have used FreeBSD servers, including Yahoo! and Hotmail. (The rumor is that Microsoft has made every effort to ween Hotmail off any open-source operating system, since open source doesn't support Microsoft's desire to dominate the server world.) One of the most attractive features of FreeBSD to business is the word "free." If a company is looking at installing a number of servers, it's difficult to argue with the economics.

ComputorEdge uses FreeBSD for both its Web servers and e-mail servers. The economic benefits don't end at the operating system. Apache for Web servers and Postfix for e-mail servers are both supported open-source programs and are among the most widely used software packages in the world. They are reliable and stable programs when running on either the BSD or Linux operating systems.

FreeBSD includes a huge database of free software via its ports system. The ports system makes it relatively easy to compile and install a variety of software. Almost everything that runs on Linux will run on FreeBSD.

The Learning Curve

People who are accustomed to using Microsoft Windows or the Macintosh interface may find a bit of a learning curve associated with installing Unix-compliant servers. While there are user-friendly, window-oriented shells, many of the systems people prefer to work directly from the prompt. This is similar to the old MS-DOS operating system or the current Windows Command windows. (See Figure 1.) The screen shown is via a remote SSH login over an SSL VPN router, but it is exactly what would be seen with a local login.



The server programs, such as Apache Web server and Postfix e-mail server, actually use configuration files that are a set of parameters written in plain text. A simple text editor is all that's needed to make changes in the software setup. (See Figure 2.)



While this type of configuration file may be confusing for someone accustomed to clicking buttons and toggles, as you can see, there are usually extensive notes explaining each parameter. After regularly working with a text-based configuration file, the operator actually has more direct control over the software, since it is almost impossible for a user-friendly configuration program to account for all possibilities. Once the configuration file is edited, the software is updated by merely restarting the program. Unlike Microsoft Windows, the reboot to update software changes is almost unheard of.

Many of commands and programs can be included in simple scripts that make configuration much easier. For example, the firewall is configured with the ipfw (IP firewall) command. On our servers, there is a text file you can use to update the firewall. It is a written script rather than a configuration file. It's not included with FreeBSD. Instead, the ipfw command is invoked in the script. People will generally have a setup such as this for maintaining their firewall, but not necessarily. There is no documented template file included for it, although its use is recommended in the FreeBSD handbook. (The FreeBSD Handbook is a well-written online document that covers all the major aspects of FreeBSD. In most cases, it includes the exact steps the administrator will need to take for any given setup or task.)

Working with the firewall becomes a process of editing a simple text file, allowing the opening of network ports and acceptable IPs, then invoking the file as a script. Once the administrator gets used to directly viewing and editing text files, the visibility becomes much clearer than that found when sitting behind a user-friendly window. Ultimately, working with servers of any type will not be for everyone. However, it is possible to make the servers accessible to everyone, including Windows users.

Samba Is for Windows

One of the ports (software programs) that is readily available for FreeBSD is Samba. The term Samba comes from Microsoft's SMB (Server Message Block), which is used in its Windows network file systems. (This is not to be confused with the first Web browser for the Mac called Samba.) When installed on a Unix-like server, Samba can make directories look exactly like Windows drives and directories to anyone who is both using Windows and has access to the server. This eliminates the need for the majority of users to even understand the prompt and Unix shell commands. This has been a tremendous asset at ComputorEdge for storing and sharing files.

FreeBSD versus Linux

I'm not touting FreeBSD over Linux. Within the Unix-like community, and even within the Linux world, it's easy to find heated arguments over the various versions of operating systems. It seems that no matter what software or computer system some people use, they will fight to the death to prove theirs is the best. I can only tell you that FreeBSD works well for us. For years, ComputorEdge.com ran well on a Linux box. The only reason that we didn't continue was concerns for the age of the hardware. When we brought in new servers, we installed FreeBSD. Once Apache—the same Web server we used on the Linux computer—was installed, the movement of the site to the new machine was fairly simple.

I had to learn to use FreeBSD, but now I've developed a certain comfort level. I could go to a Linux computer and do many of the same things I do now, but there are just enough differences for it to feel foreign to me. I'm sure that this is true to some extent even when moving between versions of Linux.

The Linux world is taking many more steps toward making the individual user more comfortable with using it as a replacement for Windows. If I were looking to do that, then I would probably start with Linux. However, if your primary objective is to build a server—for the Web, e-mail, or another intensive application—it would be difficult to go wrong with FreeBSD.