In a way, server operating systems are simpler than workstation OSes. They don't need to support as wide a variety of accessories and generally don't need to run as wide a variety of applications. On the other hand, the applications they run, such as databases, Web servers, email servers, collabourative applications and application servers, can stress both the server OS and the hardware. So choosing the best server operating system can be a trial.
Ten years ago, there were two main choices for a server OS running on commodity hardware: Novell's NetWare 4 and Microsoft's Windows NT. Today, Windows 2008 is still a solid choice, and although NetWare has disappeared into history, Novell's version of Linux is a good choice as well. On the proprietary side, the options are much the same as they were 10 years ago: Unix variants that run on proprietary hardware from Sun, IBM, SGI and others.
Choosing the best server operating system depends largely on a server's function. The easiest choice for a file-and-print server that supports Windows clients running Microsoft Office is Windows 2003 or 2008. While it's possible to support Windows file shares and run a server collabouration application that supports Outlook on a Linux server, it's more complex to set up and run smoothly. On the other hand, a file server supporting Linux workstations or an outward-facing Web server or application server is no more difficult to set up on Linux than on Windows and will probably be more secure in the default configuration and less of a pain to maintain over time.
Windows vs. Linux: Installation, maintenance and security
Both Windows and Linux offer pros and cons. Windows is easy to install and run in its default mode, includes an array of drivers for virtually any type of hardware and has the widest variety of software available. On the other hand, it suffers from frequent security problems and requires critical patches that usually involve rebooting. It is also expensive, from the initial purchase price of the OS and applications to the ongoing maintenance required to keep it stable and updated. Linux requires careful consideration of available hardware drivers that are appropriate for your hardware (including the motherboard) and whether newly released hardware (such as Intel i7 motherboards) is supported for. It also requires more knowledge to install and run the OS and applications. But at the same time, Linux is generally more stable and secure than Windows, especially the Enterprise editions available from Red Hat and Novell, which use kernel versions that are long-standing enough to have become completely stable.
Other OS considerations: Pricing, support and specialised options
Both Windows and Linux offer a sometimes bewildering variety of options. On the Microsoft side, we have Windows Server 2003 in Standard, Enterprise and Datacentre editions, with 32- and 64-bit versions of each, in addition to specialised options like the SMB edition (for small and medium-sized businesses). Windows Server 2008 presents similar options. Pricing can vary dramatically depending on the number of copies purchased and whether you sign up for the yearly maintenance agreement or the Enterprise-volume licensing plan. Linux has an even greater variety of options. Server-oriented versions of Linux are available from vendors such as Red Hat and Novell with 24/7 support and other options. Less expensive versions can be found at Xandros, MEPIS and CentOS, among others, while free versions such as Debian, Ubuntu and Red Hat's Fedora offer a low-cost way to get started.
From the most to least expensive, the biggest difference between Linux versions is not the quality of the software or the available drivers, but rather the support. If you're willing to dig into online support forums, you may find that you can get quicker support for some free versions than you can with commercially supported versions. But it is reassuring to have a 24/7 support number to call, especially in a corporate environment. Buying hardware and an OS together can also guarantee that all installed hardware is supported. Otherwise, it may require research to ensure that the motherboard, chipset, RAID adapter, network adapter, Fibre Channel host bus adapter and other elements are supported by the Linux version you're considering.
There are other non-Linux options for commodity servers, including BeOS, OpenSolaris and several Berkley Software Distribution variants. These server OS options offer better protection against hackers and security, but they are even more limited than Linux in terms of hardware and software supported by the OS.
ABOUT THE AUTHOR: Logan Harbaugh is a freelance reviewer, network systems analyst and consultant, specialising in reviews of network hardware and software, including network operating systems, clustering, load balancing, network-attached storage and storage area networks, traffic simulation, network management and server hardware.
