iMac HDD Repair Failed with Exit Code 8

General
1

I was running Logic Pro X on my iMac (macOS Catalina); suddenly, my Mac became very slow to the extent that it was difficult to shut down.

It wouldn’t restart normally or enter Safe Mode, but I managed to access macOS Recovery Mode. In Disk Utility, I found two APFS volumes: HDD and HDD-Data. I repaired both volumes with First Aid, but the HDD volume failed with exit code 8.

Is the data safe on the HDD-Data volume? I don’t want to download the entire Logic suite again!

I’ve tried reinstalling macOS twice but they all failed. Should I reformat the internal drive and try to reinstall macOS again?

2

It’s reasonable to reformat your internal hard drive before trying to reinstall macOS again. It’s possible that your internal hard drive is corrupted and a reformat can help you regain a clean system.

But remember, reformatting the drive will erase everything on it. If this iMac has valuable data, you should recover it from Recovery Mode with data recovery software first.

3

Exit code 8 in Disk Utility’s First Aid typically indicates that there are issues with the disk that cannot be repaired. This could be due to various reasons, such as:

  1. Disk corruption: The file system may be too damaged for First Aid to fix.
  2. Hardware issues: There may be physical problems with the drive itself.
  3. Unmountable disk: The disk might not be properly unmounted or accessible.
4

Try to perform a clean install first like you said. If you still can’t reinstall macOS, create a bootable USB installer and boot from the USB to install it.