• Enter df -ht to show the diskspace usage within the filesystem.
• If you want to observe the disk usage of specific directories within the filesystem, you can use the du command:
  • Enter du -h to present a human-readable view of subdirectories within the current working directory.
  • Enter du -sh to present a human-readable sum of the diskspace used by subdirectories within the current working directory. For example, to show how much total diskspace you're using within your /opt (user installed software directory):

# cd /opt
# du -sh
1.2GB