What will Panic teach you?

What will Panic! teach you?

Ever since UNIX existed, there have been a slowly growing number of people who specialize in the black art of UNIX system crash dump analysis. These folks are able to analyze the postmortem files created when a UNIX system crashes and glean some idea of the cause.

System crash dump analysis is normally something only the gurus handle. Analysis of dumps is usually a trade secret passed on from the senior gurus to the juniors. Few, if any, courses or books exist on the topic. However, as UNIX continues to make its way deeper and deeper into the commercial world, we believe it's time to share some of the tricks of the trade.

Some UNIX gurus will tell you that a book can't be written about this subject. UNIX system crash dump analysis is simply too technical and requires access to the highly coveted and rather expensive UNIX source code. Another argument against a book on this topic is that the kernel, the heart of the UNIX operating system, continues to evolve . How can someone write a book that aims at a moving target?

While we understand these valid points of view, we also see the necessity and desire for general knowledge in this subject area in the UNIX user world as well as in UNIX service and support organizations. True, due to licensing agreements, we cannot show you yesterday 's or today's UNIX source code in a compilable format; however, we certainly can get you started in the right direction when it comes to figuring out why your computer decided to suddenly keel over.

How will we do this? Well, for starters, together we will explore some of the files in the /usr/include directories. These files, known as "header files," provide great insights into UNIX and are actually the only part of the source tree that is normally provided to users on UNIX systems. We will show you how to interpret the valuable information tucked away in these files and how to use the data there.

In some cases, the demonstrations in this book will quite clearly point you to your system's problem and a solution. When a solution is not immediately obvious, usually due to a need to dive into the source code itself, we show you how to collect the most useful information available, which in turn you can forward to your system vendor. The more detail of the problem you can provide up front, the sooner your vendor can find a solution for you.

In the case of some vendors , once you've collected some system crash dump information, you may find your problem and the solution provided in a customer service newsletter, technical bulletins , or other post-sales support media provided by your vendor. For example, Sun customers may arrange to receive SunSolve , the SunService ^sm information databases provided on CD-ROM, which provides this type of problem-and-resolution information along with much more technical data.