I'm wiping an older iMac (Catalina) for disposal. I followed the instructions in support doc HT201065 and it appears to have erased the HD - Data partition, but not the system part. When I try to reinstall Catalina or reinstall from Time Machine backup, it fails, saying I have an incomplete system.
What do I try next?
Thanks in advance.
Rob
iMac 27″, macOS 10.15
Sometimes you have to go thru the erasure in steps with Disk Utility.
Try this:
1 - make sure E is mounted and then erase.
2 - make sure D is mounted and then erase.
3 - select C and erase.
4 - select B and erase;
5 - finally select A and erase.
This has worked for me. The key is making sure the early volumes are mounted and sometimes that takes unmounting them and then remounting before erasing.
The support doc said to erase the boot drive using "Erase Group" under the erase tab. That's what I did. At one point after, when trying to erase the system (the only partition left on the drive), it said kextcache was running, preventing erasure.
There was no parent container in the middle of the process. So, I started over, zapping PRAM. Then Disk Utility was able to erase it and installation of a fresh MacOS is in process.
Thanks!
Erase failure
