System Administration

Configure the time zone (TZ) on Linux systems

Having the right time zone on Linux systems helps with troubleshooting. Learn how to see and configure the right time zone on most Linux distributions.

Summary

Having the right time set on a Linux system is important for data synchronization, forensics, and troubleshooting. Next step is to configure the correct time zone. This article will help you:

  • See the current time configuration
  • Learn how to configure the time zone

Time zone information

We will have a look on how to check and configure the time zone on Linux systems.

Show current time zone

Most new Linux distributions use systemd now. With the timedatectl command we can quickly see the existing time information, including the time zone.

Understanding memory information on Linux systems

Linux memory management is an extensive subject. This guide helps you understanding the how to analyze it and obtain available memory information.

Summary

Every operating system needs memory to store program code segments and data. This is also true for Linux systems. The problem: there is a lot of information available regarding memory usage and its behavior. Let’s discover how Linux manages its memory and how we can gather memory information.

After reading this guide, you will be able to:

  • Show the total amount of memory
  • Display all memory details
  • Understand the details listed in /proc/meminfo
  • Use tools like dmesg, dmidecode, free, and vmstat

Linux memory information

Random access memory

When we talk about memory in this article, we usually mean random access memory (RAM). This is the memory which can be used for both showing and storing data. Typically we will find in this type of memory the programs that are running on the system, including the Linux kernel itself. Besides the program code, memory also stores a lot of data. A good example is when you are running a MySQL database server. The program itself is relatively small, the data itself is huge. So we will also have a look at tuning programs and their memory usage, as this is typically a problem with memory-hungry programs.

How to use grep (with examples)

Grep is a powerful utility on Linux. Want to get more out of the tool? This article will show you how to use it including many practical examples.

Summary

The grep command is one of the oldest tools for Linux and other platforms. Actually, it is older than Linux itself. It was written by Ken Thompson more than 45 years ago! The name grep stands for “globally regular expression print”. This name comes from its predecessor ed and the specific mode in which you would globally search, using a regular expression, and print the output. The related command was “g/re/p”. For more history, have a look at the Wikipedia entry. Otherwise, let’s dive into the tool and get to know some practical grep examples for daily usage.

Mosh, the SSH Alternative Option for System Administration

Learn about Mosh, an alternative for SSH. Let's dive into the reasons why it makes sense to learn about Mosh.

Summary

Mosh, or mobile shell, is the ideal tool for remote system administration. While SSH is great, Mosh beats it in several areas. Let’s dive into the reasons why it makes sense to learn about Mosh.

Pros

Session Resumption

Remember the last time your connection was interrupted? It it frustrating and sometimes even leads to losing some of your work. The stable TCP connection is not always a blessing. Mosh comes to the rescue, especially for less stable connections. It solves this issue by picking up where you left. Mosh has a roaming function, allowing you to even between connections. Very useful when you are on the move, or your WiFi connection provides you suddenly with a new IP lease. No longer you need to run everything in a screen session.