When I was first got started with administrating Linux and Unix servers I was working in an environment where there were tons of adhoc scripts that other admins wrote. From time to time I would find myself troubleshooting why one of those scripts suddenly stopped working. Sometimes the scripts would be well written and easy to understand, other times they were clunky and confusing.
While troubleshooting the poorly written scripts was always a hassle at the time, it taught me an important lesson....
Configuration management and automation tools like SaltStack are great, they allow us to deploy a configuration change to thousands of servers with out much effort. However, while these tools are powerful and give us greater control of our environment they can also be dangerous. Since you can roll out a configuration change to all of your servers at once, it is easy for that change to break all of your servers at once....
If you haven't seen it yet there is a new troubleshooting tool out called sysdig. It's been touted as strace meets tcpdump and well, it seems like it is living up to the hype. I would actually rather compare sysdig to SystemTap meets tcpdump, as it has the command line syntax of tcpdump but the power of SystemTap.
In this article I am going to cover some basic and cool examples for sysdig, for a more complete list you can look over the sysdig wiki....
One of my biggest pet peeves as a Linux sysadmin is when I see users, or even other sysadmins using kill -9 on the first attempt to terminate a process. The reason this bugs me so much is because it shows either a lack of understanding of the kill command or just plain laziness. Rather than going on a long rant about why this is bad, I wanted to write an article about the kill command and how signal works in Linux....
Today is very much a “back to the basics” kind of day. In this article I am going to cover one of the most basic commands in Linux; the cd command. While today's article might be basic; it is always good even for experienced sysadmins, to look back at some of the basics and see if there are ways to improve your command line skills and Linux knowledge.
The Linux/Unix directory structure Before getting into how to change to another directory, let's take a minute to cover how Linux's directory structure is laid out....