Error -69877: Couldn't Open Disk
Hello
I am really struggling to fix a problem I seem to have created after trying to help a friend install Windows 10 using Bootcamp (after he complained that BootCamp assistant would throw an error stating it couldn't locate a Windows partition.
Effectively the issue is that I seem to be stuck with my main HDD formatted in Windows NTFS and unable to erase the disk (using 'DiskUtil' in Mac Recovery Mode) as it throws an error:
(-69877: Couldn't open device)
The Mac is a 2015 Model 32GB iMac which has a 1TB HDD (disk1) and SSD Drive (disk0)
diskutil list
diskutil info disk1
diskutil info disk1s1
Here it looks like the disk has been successfully unmounted
diskutil unmountDisk force disk1
I then try to erase disk1 however this throws up the aforementioned error code -69877
diskutil eraseDisk apfs MAC-HD /dev/disk1
From the above, it's just not clear what my next move is, as I have tried to remove the disk volume (disk1s1) separately to no avail & I have also tried to re-partition disk1 using a different format:
diskutil partitionDisk /dev/disk1 GPT APFS MAC-HD R
If anyone has any suggestions on what I could try next to resolve this, I would be externally grateful.
Thanks in advance
Matt
iMac Line (2012 and Later)