How to fix iMac won't boot after APFS conversion?

By Katrina | Posted to Mac Data Recovery on July 26th, 2018 |

I converted my iMac 5K 1TB hard disk to APFS using disk utility. The system allowed the conversion, but now I am stuck with a MESS and there appears to be no way out. The iMac repeatedly booted into Recovery mode several times. Disk Utility shows a "container disk2" in addition to my "iMac 5K HD". How to fix iMac won't boot after APFS conversion?

As APFS is improved in many aspects than previous HFS and HFS+, most of us can't wait to convert our internal/external disks to APFS. But some users have met some troubles after APFS conversion, such as iMac not booting after APFS conversion, Mac stuck on loading/login screen or Mac computer won't start/boot. This passage will help us fix the problem that iMac won't boot after converting to APFS.

Why iMac won't boot after APFS conversion?

Firstly, when we convert HFS+ to APFS, if the previous HFS+ has some file system errors, the process of conversion will be stuck with a mess. Secondly, if the process of conversion is interrupted due to sudden power failure or others, the file system on the disk will get corrupted and APFS conversion failed on iMac. When the APFS boot disk on iMac is corrupted, we will suffer from sudden system shutdown, blue screen of death, stuck on Spinning Circle and freezing randomly.

How to fix iMac won't boot after APFS conversion?

It's not easy to fix iMac won't boot after APFS conversion as we can't start our Mac machine as usual. Here are two effective solutions and we can have a try.

Solution 1: Repair the corrupted APFS boot volume with Disk Utility in Recovery Mode

1. Boot to Recovery Mode by restarting iMac and pressing & holding down Command + R keys at startup.

2. Select Disk Utility and click Continue.

3. In the sidebar, select the corrupted APFS boot volume we wish to repair.

4. Click the First Aid button.

5. Click Repair Disk.

Solution 2: Recover lost data from corrupted APFS boot volume and reformat the volume

Here recommend we the best Mac data recovery software - iBoysoft Mac Data Recovery, which can recover lost data from corrupted APFS boot disk, recover lost data from encrypted APFS volume, recover lost data from formatted, unreadable, unmountable, inaccessible APFS drive, recover deleted/lost data from APFS partition. It supports almost all storage devices like hard drive, external hard drive, USB flash drive, SD card, memory card, pen drive, digital camera, etc.

Method 1:If you have only one unbootable Mac computer

iBoysoft Data Recovery allows you to run it in Mac Recovery Mode. The following are steps to recover lost data from unbootable iMac in Recovery Mode. This method is easier and more efficient.

Related: How to run iBoysoft Mac Data Recovery in Recovery Mode

Step 1: In the Apple menu, choose "Restart" or press the power button to turn on your Mac.

Step 2: As the computer restarts, press and hold the COMMAND+OPTION+R keys immediately to boot your Mac into Recovery Mode.

Step 3: Choose a network for your Mac. You need to make your Mac connected to the Internet all the time.

Step 4: Pull down the "Utilities" menu from the top of the screen. Type in the following command lines and then hit Enter to launch iBoysoft Mac Data Recovery through iBoysoft Server:

sh <(curl

Step 5: After launching iBoysoft Mac Data Recovery, please select the iMac internal hard drive. Then click the "Next" button to start scanning for lost files on the drive.

Step 6: Preview the scanning results, and choose the files you want to get back.

Step 7: Click the "Recover" button to get lost data back.

Method 1:If you have two Mac computers

Step 1: Create a bootable drive on the healthy Mac computer.

  1. Download, install and launch iBoysoft Mac Data Recovery on the healthy computer.
  2. Click iBoysoft Data Recovery on top left menu bar and then select "Create Boot Drive".
  3. iBoysoft Data Recovery create bootable drive

  4. Connect a USB drive to the healthy Mac, and choose it as the media to create a bootable drive on.
  5. iBoysoft Data Recovery create bootable drive

  6. Click "Make bootable" button to begin the creation process. Wait a moment while it is creating the bootable drive.
  7. Note: This process will erase all data on the USB drive. So please back up important files on the drive.

  8. When the process completed, you'll see a the following window showing the next steps to recover lost data.
  9. iBoysoft Data Recovery create bootable drive

Step 2: Recover lost data from the unbootable iMac.

  1. Insert the iBoysoft Mac Data Recovery bootable USB drive into your iMac.
  2. Restart the Mac computer and hold down the Option key (⌥) simultaneously.
  3. Select iBoysoft Mac Data Recovery from the boot options to launch iBoysoft Mac Data Recovery.
  4. Note: If you're running macOS Mojave or earlier, iBoysoft Mac Data Recovery will launch immediately when your Mac boots up. But, if your Mac is running macOS Catalina, you need two additional steps to launch this program.

  5. Wait for your Mac to boot up, open "Terminal" application from "Utilities" drop-down menu.
  6. Open Terminal

  7. Run the following command:
  8. 'Volumes/Image Volume/'

    Launch iBoysoft Mac Data Recovery Command

  9. Choose the iMac internal hard drive and click the "Next" button.
  10. Preview the scanning results, choose the files and then click "Recover".

Now, reformat the corrupted APFS boot disk.

1. Go to Disk Utility in Recovery Mode.

2. Select the corrupted APFS boot disk at left, then click Erase tab.

3. Click the erase tab on the top of the Window.

4. Enter the related info and click the "Erase" button.


Katrina is a data recovery expert @iBoysoft who loves to help readers solve various data recovery problems.