Which of the following commands is used to display disk usage in RHEL?

The command that is used to display disk usage in RHEL is indeed "du". The "du" command, which stands for "disk usage," provides a summary of the disk space used by files and directories. It can show the size of individual directories, helping users understand how space is being utilized within the filesystem. By default, running "du" will display the size of files and directories recursively, but it can also be modified with options to display more specific information, such as human-readable sizes or aggregated totals for directories.

On the other hand, while "df" is also related to disk usage, it serves a different purpose. The "df" command shows the amount of disk space used and available on file systems, providing an overview of the entire storage capacity rather than focusing on specific directories or files. "lsblk" lists block devices and their attributes, which includes information about storage devices but does not provide specific usage details for the contents of those devices. Lastly, "diskusage" is not a recognized command in RHEL, making it an invalid choice.

Understanding the distinctions between these commands is crucial for effectively managing disk space and performing system administration tasks in a RHEL environment.