Hello,
i was just checking my harddisk using Disk Utility (Applications –> Utilities –> Disk Utility) as it reports some problems on it. As i have my Apple Installation Medium at work, i had to solve that without that help.

So the main idea was booting my MacBookPro into single-user mode and repairing it by hand.

Step by Step:

• Reboot your Mac. Hold “Command + S” pressed until your Mac has booted into command-line (Single-User Mode)
• Enter the following command to start FSCK: fsck -yf
• Wait until FSCK finished the repair (can take some minutes)
• Then do one of the next 2 things:
  • Reboot using the following command: reboot
  • Shutdown using the following command: shutdown -h now
• Finally fell happy with your fixed harddrive

You can run FSCK from time to time to check your filesystem just for testing issues.
Read more about Disk-Problems, Disk Utility and other tools/commands in the following Apple article.

Best regards
fidel

Tags: cli, fsck, fsck -yf, howto, repair, repair disk permissions, single user mode