Last night my iMac attempted to automatically install macOS 10.15.1 coming from one of the betas (can’t recall if it was the final beta). The installation failed, saying “too many levels of remote in path,” which from what I’ve seen suggests that the installer was trying to mount a volume that was already mounted and had no clue how to recover.
I’ve seen scattered reports of others facing similar issues, and I want to go through what I tried and what worked to get me back up and running in hopes that it helps someone else, since Apple hasn’t pulled the update and I know that there are people who can’t afford to lose a day of work on issues like this.
Attempt 1: Retry installation by restarting as suggested by the error screen. Failed, same reason.
Attempt 2: Attempt to reinstall macOS through Recovery. Failed, same reason.
Attempt 3: Try to boot into safe mode. Kernel panic.
Attempt 4: Attempt to reinstall macOS through Internet Recovery. Failed — “a required download is missing.” Plus, it seems like the OS X Yosemite recovery OS wasn’t a fan of APFS (not surprising).
Attempt 5: Attempt to reinstall using bootable installation media created from a second Mac. Failed, same reason as Attempts 1 and 2.
Attempt 6: Do a clean install on a new APFS volume using bootable installation media. Success! (Then during the install, migrate user data from the broken APFS volume to the new APFS volume — everything is just as it was before.)
I’m glad Attempt 6 worked, because that was my last-ditch plan short of wiping the SSD. 6.5 hours later, I’m back up and running. In retrospect, I figure that I could probably have tried the strategy from Attempt 6 on Attempt 2 and likely saved myself quite a bit of time, but I figured I’d share my experience here in case anyone else runs into it.
The key point: For whatever reason, the upgrade path for my machine was broken, but running a clean install worked. That’s probably worth a shot for those running into issues, but do be aware that, since you’re duplicating much of the data on disk, my workaround requires that you’re using less than 50% (probably less than that, for overhead) of disk space or that you can otherwise copy the disk contents to another disk for migration.
I’ve seen scattered reports of others facing similar issues, and I want to go through what I tried and what worked to get me back up and running in hopes that it helps someone else, since Apple hasn’t pulled the update and I know that there are people who can’t afford to lose a day of work on issues like this.
Attempt 1: Retry installation by restarting as suggested by the error screen. Failed, same reason.
Attempt 2: Attempt to reinstall macOS through Recovery. Failed, same reason.
Attempt 3: Try to boot into safe mode. Kernel panic.
Attempt 4: Attempt to reinstall macOS through Internet Recovery. Failed — “a required download is missing.” Plus, it seems like the OS X Yosemite recovery OS wasn’t a fan of APFS (not surprising).
Attempt 5: Attempt to reinstall using bootable installation media created from a second Mac. Failed, same reason as Attempts 1 and 2.
Attempt 6: Do a clean install on a new APFS volume using bootable installation media. Success! (Then during the install, migrate user data from the broken APFS volume to the new APFS volume — everything is just as it was before.)
I’m glad Attempt 6 worked, because that was my last-ditch plan short of wiping the SSD. 6.5 hours later, I’m back up and running. In retrospect, I figure that I could probably have tried the strategy from Attempt 6 on Attempt 2 and likely saved myself quite a bit of time, but I figured I’d share my experience here in case anyone else runs into it.
The key point: For whatever reason, the upgrade path for my machine was broken, but running a clean install worked. That’s probably worth a shot for those running into issues, but do be aware that, since you’re duplicating much of the data on disk, my workaround requires that you’re using less than 50% (probably less than that, for overhead) of disk space or that you can otherwise copy the disk contents to another disk for migration.