I'm really worried, and I'm hoping that you guys can help me salvage some files. Here's what happened:

This morning I woke my iMac up from sleep, but it was hardly responding. I would click something and it would show the colorwheel spinning for 30 seconds before responding. So I rebooted, but then it got stuck on the apple logo with the loading symbol for about 15 minutes, then it started osx but it responded even less and the desktop background disappeared every 20 seconds and turned grey.

So I booted into recovery mode and tried to verify the HD, which failed. Then I tried repairing it but it failed again, saying that I should backup my files and repartition my HD. I have an external HD, but it doesn't have enough space for me to save an image of my entire HD to it. So I'm trying to backup files manually through the terminal, but that's not working either. At first I couldn't even see my HD from the terminal in recovery mode (like it wasn't mounted). After rebooting a couple of times I can now access my HD from the terminal in recovery, but when I try to copy a file to my external drive it gives an "input/output error" most of the time.

This all sounds really bad to me. Is there anything I can do?

ps: I tried booting into my windows bootcamp partition but that didn't work. The error message said something about inserting a boot cd if I remember correctly.

  • 1
    Spinrite (grc.com/sr/spinrite.htm) will most likely do the job, even if it's just for one final read to recover your data and swap out the drive. It's a paid product but I can at least attest to it doing it's job, and it's good for preventative maintenance too. There is a test version that works on macs and the up and coming version should also. If you have a PC you can stick the drive in there and it will work (it doesn't have to be a format it can understand, as long as it can access the drive it will work)
    – lc.
    Commented Oct 7, 2014 at 15:56

4 Answers 4


I had this problem too, the best thing you can do is replace the harddrive since it will eventually break beyond repair. Macs are quite sensitive to faulty hdd's so there is a good chance you can still use the drive as external drive and get your data from it.

so: Replace the drive yourself if you can (ifixit) or have it replaced Get a hard drive enclosure for your old drive plug it in your imac and drag back the files you still need

Once you've removed the failing/failed drive, you can then use an inexpensive USB to SATA adapter and see if any of the off-the-shelf file recovery software can read some of your data from the drive. Data Rescue might be a good tool to start with since the free demo will tell you what it might be able to recover before you have to spend $$ on the software.

Lastly, sending the failed drive into a professional will cost $$$ but if you really need the files or pictures back, that's often the best chance of success.

  • Repeatable and early IO errors when reading a disk are almost always fatal hardware errors with the drive. You could try reseating the cables or removing the drive and connecting to another computer, but those tend to be very rare causes of this failure.
    – bmike
    Commented Oct 7, 2014 at 13:32
  • Thanks. I managed to save a couple of files through the terminal (some of them didn't give input/output errors) and then I ended up formatting the volume with the hope of reinstalling the OS on it. Reinstalling worked, but after rebooting it just hangs on the apple bootscreen. So I guess my HD is really dead :(
    – Bart
    Commented Oct 7, 2014 at 14:05

I would try to mount your hard drive via "target disk mode". This will require another computer but works much better if possible.

Support page for transferring files via target mode.


  • This is what I would try as well, although if the hard drive is physically failing, it might be difficult. It's definitely worth a shot, though.
    – krs013
    Commented Oct 7, 2014 at 16:26

I've seen this happen a few times in the district i work for. We have almost 13,000 macs total. What I usually do is boot the machine with the bad hdd into target disk mode by holding the T key at startup. Once its in target disk mode you can plug it into another mac via thunderbolt and it should show up in Finder. If it doesn't show up in finder then open disk utility and try to repair it which will probably fail, but it will usually allow it to populate in Finder. You can then copy the files off that are most important.

  • This is great advice. See the Data Rescue link that I edited into dennismuys's answer since you can run that in target disk mode if you have another Mac as this answer suggests.
    – bmike
    Commented Oct 7, 2014 at 13:31
  • Thanks. Unfortunately I didn't have any cables to connect my laptop to my iMac and I ended up erasing the disk. In the case of the bad HDD's at your job, is it usually a hardware problem and you just replace it? Or do you manage to save them somehow?
    – Bart
    Commented Oct 7, 2014 at 14:07
  • Sometimes we can salvage the hdd by reimaging the machine. If it will not take a fresh install of OS X then it is definitely a failing hard disk.
    – Andy Batey
    Commented Oct 7, 2014 at 14:17
  • In my case I have 2 partitions and was able to reformat them, but not to remove the second partition. So I did a clean install on the first partition, which completed successfully. But then it rebooted and just kept hanging on the apple boot screen.
    – Bart
    Commented Oct 7, 2014 at 14:27

Officially, I'm going to say find a cheap software solution or a professional that your comfortable with, but ...

Unofficially, I've had success sticking my drive in the freezer for a few hours and trying standard recovery again(I'm not telling you this...I'll disavow it)

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