Introduction
The df (disk free) command is an essential tool in Linux for displaying detailed information about disk space usage. This command is especially useful for monitoring and managing your system's storage resources. This tutorial will walk you through the basics of df, showing you how to use it in various scenarios to improve your efficiency in managing Linux systems.
Prerequisites
Before you begin, make sure you have:
- An installed and working Linux system.
- Command line (terminal) access.
Installation
The df command is usually preinstalled on all Linux distributions. However, if for some reason it is not available, you can install it using your distribution's package manager. For example, on Debian/Ubuntu:
sudo apt-get install coreutils
On Red Hat/CentOS:
sudo yum install coreutils
Basic usage
The simplest way to use df is to get an overview of disk space usage on all mounted partitions:
df
This command will print a table with information about each partition, including file system, total size, used space, available space, and mount point.
Advanced usage
View in megabytes or gigabytes
To display the size in megabytes or gigabytes, use the -m or -h options respectively:
df -m
df -h
The -h (human-readable) option is particularly useful because it formats the size into a more human-readable format, such as MB or GB.
View Information about a specific file system
You can get information about a specific file system by specifying the mount point:
df /dev/sda1
View information about all file systems including unmounted ones
To display information about all filesystems, including unmounted ones, use the -a option:
df -a
View information about specific file systems types
You can filter filesystems by type using the -t option followed by the filesystem type:
df -t ext4
This command will only show ext4 file systems.
Practical examples
Example 1: disk space monitoring
Suppose we want to regularly monitor the disk space of our main partition:
df -h /Example 2: check disk space on all partitions
To get a complete overview of disk space on all partitions:
df -hT
The -T option also shows the file system type.
Example 3: checking disk space on unmounted file systems
To check disk space on all file systems, including unmounted ones:
df -ah
Conclusion
The df command is an essential tool for anyone working with Linux systems. With its many options, df allows you to monitor and manage your system's storage resources efficiently and accurately. Experiment with the various flags and combinations to take full advantage of this command's potential.
