My 2014 Mac Mini was doing an update to the latest version of Big Sur this morning and hund after restarting. I gave it a couple of hours and then rebooted it. Ii will now only start in recovery mode and only recognises the Time machine Thunderbolt disk that is attached. It sees the recovery disk but not the hard drive itself. I cannot even see the disk to erase it and re install. Any advice would be greatly appreciated before I order a replacement SSD from Amazon.
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Mac MIni not recognising HD after failed Big Sur update
- Thread starter sajr
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Make sure that you have "show all devices" selected in Disk Utility. If the disk still doesn't show at that point, you'll need to replace it.
What you need to do:
Try starting in INTERNET recovery (NOT "the recovery partition").
Command-OPTION-R
at boot.
If you connect to the net using wifi, you'll need your wifi password.
The internet utilities take a while to load -- be patient.
When the utilities are loaded, open disk utility.
Go to the "view" menu and choose "show ALL devices".
Does this change anything?
Quit disk utility and open the OS installer.
Even if you can now "see" the internal drive, you might not be able to restore the OS on it.
But... try an OS install/reinstall first.
If that doesn't work...
You might have to erase the ENTIRE drive and start over.
Hope you have a backup...
Try starting in INTERNET recovery (NOT "the recovery partition").
Command-OPTION-R
at boot.
If you connect to the net using wifi, you'll need your wifi password.
The internet utilities take a while to load -- be patient.
When the utilities are loaded, open disk utility.
Go to the "view" menu and choose "show ALL devices".
Does this change anything?
Quit disk utility and open the OS installer.
Even if you can now "see" the internal drive, you might not be able to restore the OS on it.
But... try an OS install/reinstall first.
If that doesn't work...
You might have to erase the ENTIRE drive and start over.
Hope you have a backup...
Okay I managed to mount the the disk of the mini using target disk mode and could erase it however still not showing when I boot the mini using recovery mode which seems to be using Sierra. Perhaps because of the age of the model. Therefore I am downloading the bIg Sur installer and am going to try and install via Target disk mode.
Sierra may not see the disk if it's formatted as APFS. Don't try to install Big Sur by Target Disk mode.
You can miss things like firmware updates and the installer may make changes to the internal disk. The installer may also actively now block installing in target disk mode, but I haven't tested in quite a while. It's definitely not a supported practice.
Edit: at least as of Catalina, and probably earlier, you'll get this message and the install will be blocked: "You may not install to this volume because it is a Mac in target disk mode"