Troubleshooting a failed systemd unit (with examples)

Learn how to troubleshoot failed systemd units, examples, possible causes, and how to resolve them.


Discover the reasons why a systemd unit went into a failed state


The command nstat provides network interface statistics and can be used for monitoring and troubleshooting.


Users of the command-line are typically aware of the netstat command. The package that netstat belongs to is getting deprecated and slowly replaced with tools like ip. This is also where nstat comes in, a more modern approach to pulling in data from the kernel. Another benefit is that it can retrieve more information than netstat. This is due to the static list of metrics that netstat looks for, while nstat will parse output files from /proc.

Troubleshooting a full /boot partition on Ubuntu

Is your /boot partition full and apt can no longer install updates? Learn how to fix this issue and what you can do to prevent it.


A regular issue with systems running Ubuntu is that may fill up the /boot partition. You might have discovered it when running apt, which refused to work. That is unfortunate, as you also need apt to resolve the issue. After trying several options, we found a way to resolve this catch 22, with just three steps. Opposed to other solutions, you don’t need to move files or do other tricky things on your system.

Understanding what runs on your Linux system (and why)

Linux systems have a lot of processes running by default. Let's dive into how programs are started and how you can see all details of each running process.


Introduction Each Linux system has a bunch of processes running. Most of these processes might be familiar to you if you regularly use a command like ps or top to display them. Processes may look like just an item in a list. They are actually complicated pieces of code that are tamed by a memory manager. To truly understand how your system is running, knowledge of process (or memory) management is of great help.

Strace cheat sheet

The strace utility is diverse and helpful in performance tuning, troubleshooting, and monitoring process activity. Get the most out of this powerful tool!


Troubleshoot and monitor all processes

GPG key generation: Not enough random bytes available

A common error when creating keys with GnuPG is: Not enough random bytes available. In this article we have a look at the cause and solution.


Anyone who wants to create a new key set via GnuPG (GPG) may run into this error: We need to generate a lot of random bytes. It is a good idea to perform some other action (type on the keyboard, move the mouse, utilize the disks) during the prime generation; this gives the random number generator a better chance to gain enough entropy. Not enough random bytes available. Please do some other work to give the OS a chance to collect more entropy!

Lynis stuck during testing

How to deal with issues when running Lynis and looks like it is stuck during any testing being performed. Finding the causing in a few quick steps.


Normal Lynis scans take a few minutes to complete, therefore any test taking more than 1 minute, might be stuck during its test. Within this article we have a look at a few things you can do. When a particular test is taking a long time, the test might be stuck. However, that’s not always the case. To determine what Lynis is doing, open up a second terminal and start with running ps aux to see what processes are active.