Answer: To find out how much disk space is being used on each of the file systems on a Linux system, you can use the df command.
The df command displays information about the file system disk space usage, including the total size, used space, available space, and file system type.
To display the information for all mounted file systems, you can run the following command in a terminal:
df -h
The -h option displays the output in a human-readable format, using units such as MB (megabytes) or GB (gigabytes).
Alternatively, if you want to display the information for a specific file system, you can specify the file system path as an argument to the df command. For example:
df -h /dev/sda1
This will display the disk space usage information for the file system mounted at /dev/sda1.