Upgrading and Repairing Servers

In the Dark Ages, a Slavic king invited representatives of each of the major religionsRoman Catholicism, Greek Orthodoxy, Islam, Judaism, and othersto visit him. He wanted them to make their religions known to him so that he could pick a religion for his country to follow. Eventually he chose the Greek Orthodox religion, which is a story for another time. That parallel to this chapter becomes clear only if you've ever seen users jumping up and down over some new announcement at a MacWorld or Windows World conference. If you've witnessed to that kind of scene, you can't help but be reminded that adopting an operating system (OS) is a little bit like adopting a religion.

When you pick a network operating system (NOS)or any OS, for that matteryou face the same dilemma the Slavic king faced. All mature NOSs come with the necessary tools to support many different types of clients; a host of network services such as Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), Transmission Control Protocol/Internet Protocol (TCP/IP); a variety of file systems; and many other industry standards. In many ways Microsoft Windows Servers, Novell NetWare, Sun Solaris, Hewlett-Packard UNIX, and a variety of Linux flavors are more alike than they are dissimilar. A desktop user selects one or two OSs to run on his or her workstation, gets the religion, and lives a happy, blissful, comfortable life. If you are "lucky" enough to be in a company that has rigorously enforced a one-state computing solution on its people, life is similarly blissful. You can continue on, oblivious to the outside world.

Many companies and organizations don't have the luxury of enforcing the one-NOS solution. Their graphics and marketing departments may run on Apple Macintosh, accounting may run an Oracle software solution on UNIX, engineering may have a little of everything, from Windows Server to Linux and even older systems running MS-DOS that can't be replaced, and so on. Therefore, system administrators find themselves having to support a little bit of everything, as well as trying to make good decisions for future technology purchases. If that doesn't make things complex, then consider when Organization A merges with Organization B, and each runs different NOSs. With complexity comes a lot of headaches and chaos, but you also get some real opportunities to make decisions that can give your organization best-of-breed systems. Some choices can substantially lower a company's computing costs. Other choices may lower support costs or offer other opportunities.

This chapter presents a high-level discussion of the major NOSs in use today and describes how they might fit into a modern heterogeneous network where different types of servers are called upon to work together. The discussion in this chapter focuses on some of the known advantages and disadvantages of different server OSs, how to determine what represents a best-of-breed solution, how to make the many application directory services interoperate, and how to best manage your servers so that you aren't running around from server to server, applying fixes like the proverbial chicken with its head chopped off.