SDErrorDomain error 108 when trying to boot from external SSD, Mac Mini M2
What I have done:
"
Change your Mac startup disk - Apple Support
"Change your startup disk for every startup
- On your Mac, choose Apple menu
- > System Preferences, then click Startup Disk
- .
- If the lock at the bottom left is locked
- , click it to unlock the preference pane.
- Click the icon of the disk you want to use, then click Restart.
WARNING: When selecting a network startup volume, make sure you select a network startup volume and not a network install image. Choosing a network install image reinstalls your system software and may erase the contents of your disk. A standard network volume icon appears as a globe with a folder. A network install icon appears as a globe with a downward-pointing green arrow."
If you are seeing errors you might consider checking the disk for errors in Disk Utility.
How to repair a Mac disk with Disk Utility - Apple Support
Also, after backing up any personal files, you could consider formatting the disk and reinstalling macOS on it.
Erase and reformat a storage device in Disk Utility on Mac - Apple Support"
My issue:
I have a brand new 2023 Mac Mini M2 8GB 256GB. I am attempting to use an external SSD (NVMe in an enclosure) as the main drive.
I reformatted the external SSD to AFPS GUID and named it Ext Macintosh HD. I then downloaded the latest Sonoma today from the Mac App Store. I installed Sonoma to the external drive successfully, the Mac Mini then rebooted and it booted back up into the internal drive. I tried setting the Startup Disk to the External SSD in System Settings and then attempted to reboot and I received this message:
An error occurred while setting “Ext Macintosh HD” as the startup disk: The operation couldn’t be completed. (SDErrorDomain error 108.)
I have attempted this a few times with the same result each time.
Does anyone have any experience with this?
I read that the booting into recovery (holding down the power on button on the back of the Mac Mini) and then allowing the Mac to boot from an external drive is possible but I followed the instructions from a website and there was no setting that allowed that, just a reduction in security settings.
