Having been a SysAdmin for the past 12 or so years I can safely say that I’ve encountered and successfully resolved my fair share of issues. Some of which on platforms I would consider myself highly knowledgeable on and those that I’ve never touched in my life.

Being or becoming a highly capable SysAdmin is not trying to know everything. This is not possible, and any SysAdmin that alludes to this is both lying and frankly dangerous.
No, the key is your approach to the problems you encounter, and simply put this boils down to the questions you ask. Not questions you necessarily ask a customer/user or your peers, but the questions you ask yourself.

As you grow, develop and encounter problems, you’ll gain experience. You’ll be able to use this experience to speed up the time it takes to resolve future problems you encounter, thus turning unhappy customers or users into happy ones very quickly.

However, sooner or later your experience will fail you and you’ll find yourself going round in circles and spending an enormous amount of time and effort investigating a specific component.
Alternatively, you receive a good description of the problem that again you focus all of your attention at a specific component.

It is here that you need to remind yourself that in most cases there is a logical reason behind the cause of the problem.
Even the most accomplished of SysAdmins need to be reminded of this every now and then.
All it can often require is to take a step back, and get back to basics. Often a logical approach through the questions you ask yourself can lead you to a simple solution to what may seem to be an illogical and complex problem.

So what are these magical logical questions you should ask yourself?
Well every situation is of course going to be different, but from a high level a good starting question would be:

What is required for the component I am troubleshooting to operate successfully?

From there you can break this down into very simple questions of verification, which will either point out the problem, or at least the area to further concentrate your efforts.
Such questions could be as simple as these:

Is the device powered on?
Am I looking at the right device?
Are the supporting components/services running?
Are the supporting components/services configured correctly?
Is the component configured correctly?
Have there been recent changes to any of the above?

Very simple and high level I know, but I’m keeping this as generic as possible, but hopefully you get the picture.

Reading this back this all seems so very obvious. It may well be that it’s too obvious. I certainly wouldn’t be writing this though if it were not for being witness to and at times (though rarely!) guilty of throwing all logic out the window.

At the end of the day, it’s all just 0’s and 1’s. Trust that there is a logical reason and trust that a logical approach will prevail.

Happy troubleshooting folks!