sadmac

Modern Macs (those running OS X (X = 10) are pretty self-regulating, but now and then your Macintosh of Choice (iMac, Macbook, Macbook Pro, Mac Pro, Mac Mini will behave badly, apps will freeze or you’ll get the dreaded Kernel Panic where the display freezes and you have to reboot.

Screen Shot 2015-02-17 at 6.37.39 PM

If you have your install DVD or can start in Safe Mode (hold down the shift key after you hear the “bong”) you usually don’t need to do a FSCK repair, however, there are times where running FSCK is the best option for checking the OS X file health. Apple outlines these other options here.

FSCK IT

If your Mac is unhappy it may be time to FSCK (File System for Consistency checK).  This works on all Mac OS X up Catalina and Big Sur (Mac OS 10.15 & 11). To repair a Catalina disk error, run Disk Utility  From Mac OS 10.0 to 10.14, you can run FSCK. To run the FSCK command you have to be booted into Single User Mode and you get there like this:

  1. Restart or Start if your Mac is off.
  2. After you hear the “bong” at startup, hold down the Command (Apple Symbol: ⌘) and the “S” key (Command + S). Hold both keys down until you see a black background with white text flowing down it. This is showing the boot process textually.
  3. Once it’s complete, you’ll see at or near the bottom this line:
    :/ root#  (Or it may be your user name instead of root. )
  4. At this prompt you will type in: fsck -fy (yes, that’s a space between the “k” and the “-“)
  5. Hit Enter or Return to run the process. Depending on the size of the drive or the number of issues it may take several minutes, so be patient.
  6. At the end of the process you’ll see one of two messages:  ** The volume (name_of_volume) appears to be OK  . . . or:  ***** FILE SYSTEM WAS MODIFIED *****
  7. If it’s the latter, run it again. Anytime you get a “File System Was Modified” warning at the end of the process you have to run it until you get the “OK.”
  8. Once you get “The volume (name_of_volume) appears to be OK” type “exit” at the prompt and hit return. Your machine should now boot normally. If not, you have other, possibly bigger issues and might want to contact me for help.

FSCK can fix a number of file-system-related issues either from a power outage or just apps crashing or a kernel panic. It won’t fix everything, but it’s a great tool to have at your disposal.

JoeL