Linux du Command Tutorial with Examples

The du command is used to get information about the disk usage in Linux. The du command provides a lot of useful information about disk usage like directory size, file size, free percentage, etc.

Print File Sizes as Byte

The du command is used to list given files and directories sizes in the byte unit. There is no extra parameter. The following command lists the current working directory and its child sizes.

du 
Print File Sizes as Byte

Alternatively, we can specify different than the current working directory in order to list files and directories sizes. In this example, we will provide the absolute full path to list sizes.

du /var/log

Print File Sizes in Human Readable Format

By default the sizes are printed as byte unit which is not easy to read and understand. The human readable format can be used where the sizes are printed as kilobyte, megabyte, gigabyte etc. The -h option is used to print sizes in human readable format.

du -h /var/log

The output will be like below.

 625M    /var/log/journal/295c2cf105a140e5ab505a9e74ff560e
 625M    /var/log/journal
 252K    /var/log/apt
 1012K    /var/log/installer
 4,0K    /var/log/private
 4,0K    /var/log/gdm3
 64K    /var/log/unattended-upgrades
 4,0K    /var/log/openvpn
 4,0K    /var/log/lightdm
 40K    /var/log/cups
 4,0K    /var/log/sssd
 64K    /var/log/apache2
 4,0K    /var/log/dist-upgrade
 32K    /var/log/mysql
 4,0K    /var/log/speech-dispatcher
 629M    /var/log

Print Sizes For All Files and Directories

By default the du command prints only directory sizes with their contents. But by providing the -a option all file sizes can be also printed like below. Alternatively, the long format of the -a option can be used which is –all.

du -h -a /var/log

The output is like below. We can see that the files with *.gz and *.1 extension and their sizes are printed too.

4,0K    /var/log/vmware-network.log
 16K    /var/log/boot.log.2
 4,0K    /var/log/kern.log.2.gz
 625M    /var/log/journal
 180K    /var/log/syslog.6.gz
 1,3M    /var/log/dpkg.log.1
 4,0K    /var/log/kern.log.3.gz
 4,0K    /var/log/kern.log.1
 12K    /var/log/apt/history.log
 72K    /var/log/apt/eipp.log.xz
 96K    /var/log/apt/term.log
 32K    /var/log/apt/term.log.1.gz
...

Print Sizes By Excluding Some Files and Directories

By default the du command prints all specified files and directories sizes. But we can also exclude some files and directories by using the -X option. The -X option long-form is –exclude. Some file or directory pattern is provided which will be excluded. In the following example, we will exclude files with the “*.gz” extension.

du -X="*.gz"

Exclude Symbolic Link

Linux uses the symbolic links heavily and different directories may contain symbolic links to the other directories or paths. We can exclude the symbolic links with the -L option like below.

du -h -L /var/log

Print Total Size Of All Directories

The total sizes of the directories can be printed by using the -c option. The total size includes given directory content and all of its child directories sizes. Alternatively, the long form of the -c option can be used which is –total.

$ du -h -c /var/log
625M    /var/log/journal/295c2cf105a140e5ab505a9e74ff560e
 625M    /var/log/journal
 252K    /var/log/apt
 1012K    /var/log/installer
 4,0K    /var/log/private
 4,0K    /var/log/gdm3
 64K    /var/log/unattended-upgrades
 4,0K    /var/log/openvpn
 4,0K    /var/log/lightdm
 40K    /var/log/cups
 4,0K    /var/log/sssd
 64K    /var/log/apache2
 4,0K    /var/log/dist-upgrade
 32K    /var/log/mysql
 4,0K    /var/log/speech-dispatcher
 629M    /var/log
 629M    total

Print Sizes For Specified Level Files and Directories

By default the du command traverse all child directories and their contents. But this may be unnecessary for some situations. We can specify the directories to reverse and lower-level directories are not calculated. The -d option and the level number can be used for this operation. In the following example, we will just traverse level 1 directories and files.

du -d 1 /var/log
639020    /var/log/journal
 252    /var/log/apt
 1012    /var/log/installer
 4    /var/log/private
 4    /var/log/gdm3
 64    /var/log/unattended-upgrades
 4    /var/log/openvpn
 4    /var/log/lightdm
 40    /var/log/cups
 4    /var/log/sssd
 64    /var/log/apache2
 4    /var/log/dist-upgrade
 32    /var/log/mysql
 4    /var/log/speech-dispatcher
 644028    /var/log

Print Current Directory Size As Summary

The -s option of the du command can be used to print summary size of the file system like below.

$ du -s -h /var/log
629M    /var/log

Print Modification Time of Files and Directories

Even it is not the main job of the du command the last modification time of the directories and folders can be listed with the –time option like below.

du --time -h /var/log
625M    2020-12-20 12:41    /var/log/journal/295c2cf105a140e5ab505a9e74ff560e
 625M    2020-12-20 12:41    /var/log/journal
 252K    2020-12-18 09:50    /var/log/apt
 1012K    2020-11-02 17:23    /var/log/installer
 4,0K    2020-10-22 16:59    /var/log/private
 4,0K    2020-11-02 14:37    /var/log/gdm3
 64K    2020-12-20 11:57    /var/log/unattended-upgrades
 4,0K    2020-08-18 14:42    /var/log/openvpn
 4,0K    2020-02-07 14:40    /var/log/lightdm
 40K    2020-12-20 12:24    /var/log/cups
 4,0K    2020-11-29 00:00    /var/log/sssd
 64K    2020-12-20 00:00    /var/log/apache2
 4,0K    2020-09-23 01:59    /var/log/dist-upgrade
 32K    2020-12-20 00:00    /var/log/mysql
 4,0K    2020-08-20 01:11    /var/log/speech-dispatcher
 629M    2020-12-20 12:41    /var/log
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