I have a hard drive that is having problems on a Mac that doesn't use Time Machine or another complete backup system. I get this error when trying to repair the disk:

Error: Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files.

I have all the stuff I want backed up, but I'm curious if there is anyway to rebuild/repair it? I booted with a Ubuntu live CD and ran badblocks to check the disk with 0 errors, so hopefully that means the drive isn't going bad.

It seems I've repaired windows partitions before, so it seems weird that a Mac partition would be so fragile that there was no way to repair it.

If there is no way to just fix the partition, can I just boot into the Maverick System Recovery and erase/reinstall, or do I have to boot from the original leopard DVD and then upgrade?

  • The discussion at Should I format and upgrade to mavericks or upgrade to mavericks and format? is closely related, but not so much an exact duplicate.
    – Rob
    Mar 11, 2014 at 13:52
  • You didn't state if you have a good backup like Time Machine from before the errors happened. Do you need to make a backup or are you set in that respect?
    – bmike
    Mar 11, 2014 at 14:22
  • @bmike I hooked the drive up to another mac and copied off my user directory, so I should have all the important stuff. I don't have a time machine drive, so I can't just restore from that.
    – AndyD273
    Mar 11, 2014 at 15:06

2 Answers 2


It all depends on what is going on with the drive and unfortunately there is really no good way to tell.

I have been using Diskwarrior for YEARS and it is still my go-to disk repair tool. Drive Genius is pretty good too. I have both but always start with Diskwarrior.

These tools MIGHT be able to repair the volume issues, but it might be quicker, easier and cheaper (?) to just bite the bullet and do what the disk utility says: reformat and reinstall.

  • I agree disk warrior is the long time, go to tool for patching up software errors and making a workable catalog after disk utility gives up. I don't have any experience using it on 10.8 or later and would be 100% sure I had a version that is up to date before trying it on any drive with core storage or even the 10.9 file system. I see these tools as a last resort when no backups exist and you are trying to get a backup, and not a first resort to keep the system maintained and running well long term.
    – bmike
    Mar 11, 2014 at 14:34

Apples disk utility will repair a wide variety of errors, but also draws the line on some other errors (or likely volume and rate of of errors) and then focuses on backup and a clean re-start to that drive.

If you have a good backup or don't care to back anything up, I would just reinstall. Booting into the recovery HD and erasing the drive will start with a clean slate. At that point, the installation process will be an excellent test whether the hardware is failing or not.

Once you have evidence the hardware worked by an error-free installation and clean disk utility verify post install, at that point you can restore your backup or just commence using the clean OS install.

If you don't have a backup and can't get one using Apple's tools, then it might make sense to gIVE Disk Warrior/Drive Genius or another third-party repair tool a try to repair/recover and at least get a good backup.

I think of apple's disk utility warning similar to run-flat tires or an engine that can shut off one cylinder and still get you home or to the repair shop under limited power. The system used to keep running until it broke catastrophically, leaving people with no warning that they needed to back up their files when disk errors started happening at elevated rates.

  • I hooked it up to another Mac, and after about 30 minutes it decided to mount so I could copy my user folder off.
    – AndyD273
    Mar 11, 2014 at 15:08
  • @AndyD273 Excellent. That long fsck time is indicative of what you reported originally - multiple software errors or a failing device. Very glad you got the files off. Once you erase the drive and try reinstalling you should know which fairly quickly. Hardware doesn't get better - software is fixed immediately with an erase / repartition.
    – bmike
    Mar 11, 2014 at 15:13
  • So hopefully I have that taken care of. I just tried erasing the partition from the recovery partition, but it hung up with a preparing to erase partition message that lasted about an hour until I just command-q'd out of it. I'm downloading Mavericks to make a bootable USB so I can try fixing it from there...
    – AndyD273
    Mar 11, 2014 at 15:16
  • You could also use disk utility on the other machine to erase the Macintosh HD via target disk mode and then try rebooting into recovery.
    – bmike
    Mar 11, 2014 at 15:19

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .