It turns out that very few people dream of becoming a sysadmin as a child. Most sysadmins got their start by combining an interest in computers with another interest or skill. The combination isn't always intentional. Some people just happened to fix the right person's computer one day or got saddled with systems administration on top of their regular job duties. For others, it is the natural next step. An experienced developer who no longer feels like developing is often a great candidate to maintain the systems that the developers use. Many others move up through the ranks, starting out at the help desk and gradually gaining knowledge and responsibility. One person's career path even made a brief stop as a strip club bouncer.
For many people, myself included, there was little formal training in computers. My degree is in meteorology, and I know of several people who got started in the sciences or engineering. The reason for their success is two-fold. In academic environments, it helps to understand the science behind the work the users are doing. The other reason is that scientists and engineers are trained to think a certain way - to approach and solve problems in a logical and systematic manner. The fundamental job of a system administrator is to solve problems or anticipate future problems, so having a scientific mindset is a strong asset.
So if formal training in computers isn't necessary to become a sysadmin, what is?
The willingness to learn is key. A successful sysadmin spends a lot of time learning, whether it is about new software, new hardware, new processes, or USB missile launchers. If you want to become a sysadmin, the first thing you need to do is to start learning. The learning can be accomplished in many ways. Formal education, in the form of classes or vendor-provided training, can be very valuable. Learning at the shoulder of someone more experienced provides some gaps, but gives you knowledge that can only come from experience. And of course, there's self-education. The bulk of my early learning came from tinkering with (and breaking) my own computers, and by reading "___ For Dummies" books. It's amazing what you learn when you have to fix your mistakes.
So what do you need to learn? Everything. I won't get into the technical skills, because those will vary from position to position. I mean, you might need to know how to set up an Exchange server, or how to tune NFS performance, or how to manage a print server, or...well, you get the idea. To really be a successful sysadmin, you need to learn some indispensable, if tangential, skills. Technical documentation may be the most important skill for sysadmins, because you will at some point forget every important piece of information that you need to know. Writing documentation for users is also invaluable, especially if you want to spend less time answering questions. Project management, personnel management, and budgeting skills also come in handy.
Armed with all of this knowledge, you're ready to become a sysadmin and find out how much you don't know (hint: no matter how much you know, there's always more that you don't). Getting the first job is the hardest, and you might need to start out doing non-sysadmin work. Help desk support, programming, or anything else that gets you in the door gives you the opportunity to start learning new skills and taking on responsibilities. The only common theme among the answers I received is that there's no common education, minimum skills requirement, or career path. Each sysadmin path is unique. I'll leave you with a few of the most amusing quotes:
"I think I did something horrible to someone in a previous life and this was my punishment. Anyone else feel like that?"
"Enlisted in the Army for a completely unrelated job. Made the mistake of fixing the commander's email. Voila! I became a sysad."
"I am a sysadmin because one beautiful summer day, I found a computer laying in a field."
"Why would someone want to get into this job? I strongly suggest he get into driving heavy machinery. That's what I'm gonna do when I grow up."
Further reading:
- System Administrator on Wikipedia
- How did you become a sysadmin? discusson on Serverfault
- What makes a great sysadmin? discussion on ServerFault.
