Book Image

Learn Linux Quickly

By : Ahmed AlKabary
Book Image

Learn Linux Quickly

By: Ahmed AlKabary

Overview of this book

Linux is one of the most sought-after skills in the IT industry, with jobs involving Linux being increasingly in demand. Linux is by far the most popular operating system deployed in both public and private clouds; it is the processing power behind the majority of IoT and embedded devices. Do you use a mobile device that runs on Android? Even Android is a Linux distribution. This Linux book is a practical guide that lets you explore the power of the Linux command-line interface. Starting with the history of Linux, you'll quickly progress to the Linux filesystem hierarchy and learn a variety of basic Linux commands. You'll then understand how to make use of the extensive Linux documentation and help tools. The book shows you how to manage users and groups and takes you through the process of installing and managing software on Linux systems. As you advance, you'll discover how you can interact with Linux processes and troubleshoot network problems before learning the art of writing bash scripts and automating administrative tasks with Cron jobs. In addition to this, you'll get to create your own Linux commands and analyze various disk management techniques. By the end of this book, you'll have gained the Linux skills required to become an efficient Linux system administrator and be able to manage and work productively on Linux systems.
Table of Contents (24 chapters)

Running out of space

Let's create huge files that would consume all the available disk space in /games.

A fast way to create big files in Linux is by using the dd command. To demonstrate, let's first change to the /games directory:

root@ubuntu-linux:~# cd /games 
root@ubuntu-linux:/games#

Now you can run the following command to create a 1 GB file named bigGame:

root@ubuntu-linux:/games# dd if=/dev/zero of=bigGame bs=1G count=1 
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 1.44297 s, 744 MB/s

We have now already used more than half of the available space in /games:

root@ubuntu-linux:/games# df -h /games 
Filesystem Size Used Avail Use% Mounted on
/dev/sdb1 2.0G 1.1G 868M 55% /games

Now let's attempt to create another file named bigFish of size 3 GB:

root@ubuntu-linux:/games# dd if=/dev/zero of=bigFish bs=1G count=3 
dd: error writing 'bigFish': No space left on device
1+0 records in
0+0 records out
1016942592 bytes (1.0 GB, 970 MiB...