BACKUP my passport
Time Machine couldn’t complete the backup to “Backup 1TB Black
I deleted older backups to provide more space but still have error code.
MacBook Pro 15″, macOS 12.7
if you tired to delete anything on a time machine drive using Finder, you will probably find those double-locked files are still in the Trash. They are very difficult to remove, by design.
Time machine creates a database that includes ONE copy of files originally saved in backups created long ago. If you arbitrarily delete a backup from a certain day using Finder, some files required to complete the backup set are discarded as well. Your backup set has lost its integrity, and can no longer bring back all your files.
When you ask Time machine to remove a certain old backup, or just let it run and find the space by itself, I CONSOLIDATES old backups, making certain to keep needed files.
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You need a larger drive. Recommended size for long-term trouble-free use is more than 2.5 times the size of a Full backup of all the files on the computer. Since time machine does most of its work in the background at low priority, do not pay extra from a drive that is Fast.
You can add additional time machine backup drive at any time, and backups will alternate -- every-other backup goes to every other drive.