I am running macOS sierra on a mid 2012 MacBook Pro, and just recently came across a problem where I can no longer bypass login and got stuck on a loading screen before it eventually goes to a black screen and can no longer get into my Mac.

So, I decided to try and back up my stuff and migrate them to a new Mac I'm buying. I pop the WD Passport drive into the USB, go to the recovery mode and attempted to create a disk image backup from my MacIntosh HD onto it. But half-away, I am met with:

The operation couldn't be completed. (com.apple.diskutility error 3)
Preparing imaging engine...
Reading whole disk (apple_HFS : 0)...
Operation failed with status 5

I haven't got Time Machine activated, and I cannot even get into my Mac to use it. So I am left at a loss, trying to figure out how to create a backup.


If it fails on creating a disk image, then there may be one (damaged) file causing the problem.

Why not open the user folder and copy each sub-folder in turn and when you find the folder that fails copy the contents inside individually until you find the errant file...

Of course, it may not be a personal file causing the issue...


There are a few things you could do to get around this problem. To get into your Mac, your could boot to Recovery (Option select Recovery) or into Single User mode (CommandS)

  • Manually back up your data. You will have to reinstall your apps and re-tweak your settings, but the most critical stuff (your data) will be preserved. You can do this via Terminal:

    cp -R /Users/My_User_Name /Volumes/WD_Drive/My_User_Name_Backup

    Change My_User_Name and WD_Drive with the actual names of the folders.

  • Attempt to run Disk Utility with sudo permissions:

    sudo /Applications/Utilities/Disk\ Utility.app/Contents/MacOS/Disk\ Utility
  • Just use Migration Assistant from your new computer. While I am a huge proponent of backing up your data, since your getting a new machine, it may be easier to just transfer to the data once then begin your backup regimen. As long both Macs are connected to the same network, you can use Migration Assistant.

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