In one of the first posts of this blog I covered some basic SystemTap functionality from an email that I sent to members of my team, but I have always felt that I haven't given SystemTap as thorough of an article as this incredible tool deserves. Today I want to correct that.
For today's article I will show how to compile SystemTap scripts on one server while running the compiled module on a production server without installing debug-info or devel packages in production.
For me when it comes to useful commands xargs ranks along side commands like find, top and df; xargs is a great time saver and incredibly useful. Today I will show a few examples of usage and some of the lesser known features.
Basic Usage The xargs command is used to take the output of one command and provide it as arguments to another.
# ls [0-9]-test.xml | xargs chmod -v 644 mode of `1-test.
Linux has many tools available for troubleshooting some are easy to use, some are more advanced.
I/O Wait is an issue that requires use of some of the more advanced tools as well as an advanced usage of some of the basic tools. The reason I/O Wait is difficult to troubleshoot is due to the fact that by default there are plenty of tools to tell you that your system is I/O bound, but not as many that can narrow the problem to a specific process or processes.
Zombies don't just appear in scary movies anymore, sometimes they also appear on your Linux systems; but don't fret they are mostly harmless.
What is a Zombie Process? Before we get started I wanted to first cover what exactly a Zombie process is.
Linux and Unix both have the ability for a process to create a sub process otherwise known as a “Child Process”. Once a process creates a new sub process the first process then becomes a “Parent Process” as it has spawned a child process during its execution.