How to Check Disk Space Utilisation and Take a Backup of Directories and Files

Following this lab exercise, you should be able to understand:
- how to check disk space utilised by directories and files
- how to identify what files or directories are consuming lots of disk space
- how to take backups of files and directories
- how to compress individual files
- how to make archives of backed-up files and directories
- how to compress individual archives
- how to use the Linux and UNIX commands - df, du, tar, gzip, gunzip