Your computer often gets updates, new programs, logs that will obliviously consume disk space. You need to find how much space these objects consumed and act accordingly.
In a Linux system, you can use du command to find out disk space usage very easily.
Prerequisites
- A Linux or UNIX-like system.
- Basic understanding of the Linux command line.
- A login user with sudo privileges or root privileges
What is du command in Linux
Du command calculates the amount of disk space consumed by files under a particular directory (or subdirectories). Whereas df command gives overall space utilization of filesystem and mounted disks.
How to use du command
The du command displays disk usage in the command line. Without any options shows it displays disk usage of every directory and sub directories recursively.
Open your terminal and type du and press Enter key:
dudu Output
The output shows disk usage on the left and full path, total disk usage of each parent directory, and the last line shows a summary. There is no unit of measure indicated from this output. By default, du shows the size in 1024 bytes.
Du Command Options
Some of the main du command options:
| Options | Description |
|---|---|
| -h , --human-readable | Human Readable Format |
| -s, --summarize | Total size of a Directory |
| -a | All files and directories |
| -k | Disk usage in KB |
| -m | Disk usage in MB |
| -c, --total | Grand total size |
| --time | Show the time of the last modification |
| -X, --exclude=Pattern | Exclude files that match a pattern |
Useful Du Command with Examples
Familiarizing these commands help users to gain disk usage information easily. Let check some of the useful du commands.
Display Directory Size in Human Readable Format
The default output of du command is not user-friendly. It would be easier to understand if it prints the sizes for example 1K, 25M, 2G, etc. Type du -h command to print the size of the disk in a human-readable format.
du -h
You may also use du -h * command to print user-friendly disk usage of all files and directories in the current directory and subdirectories.
Du command has an option to set implicit behavior though -B, --block-size=SIZE. For example to set block size to 1GB:
du -h --block-size=1GDisplay Summarize Disk Usage
The du outputs a lot of information in a directory tree that may be hard to when trying to find the combined size. You may use -s to summarize disk usage of a directory.
You may also du ../<directory-name> to print disk usage one level above. I love using -h option in conjunction for more readability.
To display the combined size of a specified directory type du -sh command followed by the path of the directory.
du -sh /home/linuxopsys/Projects
Whereas, du -sh * command displays line by line the size of each directory and files in the current directory.
You may also use du -sh /path/to/file command to display individual files size.
Display disk usage of all files and directories
Type du -a to list the sizes of all files and directories including file path. The difference with other du commands is that it displays file sizes as well. You can combine -h flag to ease of reading.
du -ah
Display Directory disk usage in Kilobytes (KB units)
Type du -k option to display directory usage in Kilobytes:
du -k
Display disk usage in Megabytes (MB units)
Type du -m option to display directory usage in Kilobytes:
du -m
Display grand total size
In the previous outputs, you might have seen the total usage at the bottom of the list. It's the same but the -c flag displays the text "total" showing the grand total disk usage for the specified directory or file.
To find the total size of specified files type du -ch /directory-path/*.jpg command.
Display disk usage based on last modification time
This is an extremely useful option. The --time option print the time of the last modification of files and directories along with disk usage.
You can see it sorts by time with the newest first in the list.
Exclude files that match a pattern
On some occasions, you may want to calculate the disk usage excluding some files that match a given pattern. For example, you can use -–exclude="*.jpg" option to exclude all jpg files and calculate the total size of the directory.
du -ah --exclude="*.jpg" Projects
Conclusion
In this tutorial, we learned about du command in Linux. There are many options that we have not covered here, you can refer to du man pages for all the information or simply type man du from your terminal.
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