"If you are upgrading from macOS High Sierra, Mojave, or Catalina to Big Sur your upgrade could fail if it matches a very particular condition.
If folders in multiple directories in the location below
/private/var/folders/*/*/C/com.apple.metadata.mdworker
have more than 20,000 files your upgrade could fail.
In some situations users have reported 500,000 – 2,000,000 files!!!
This is the reason why the problem could never be reproduced.
If you build a fresh system the file counts for spotlight will be very low. You might have 20-400 entries. This would allow the upgrad to finish properly."
mrmacintosh.com
If folders in multiple directories in the location below
/private/var/folders/*/*/C/com.apple.metadata.mdworker
have more than 20,000 files your upgrade could fail.
In some situations users have reported 500,000 – 2,000,000 files!!!
This is the reason why the problem could never be reproduced.
If you build a fresh system the file counts for spotlight will be very low. You might have 20-400 entries. This would allow the upgrad to finish properly."
macOS Upgrade to Big Sur Failed! Stuck Progress Bar fix & Prevention!
MacOS Big Sur currently has an upgrade issue. In certain situations, the upgrade will fail with a stuck progress bar. How to fix the problem!
mrmacintosh.com
