Can’t empty a backup from the Bin
Q I deleted a Time Machine backup which I now can’t get rid of. Whenever I try to empty the Bin, it tells me that files in that backup are still in use. How can I remove them? by PHILIP WAKEFIELD
A macOS is now very protective of Time Machine backups, and not only sets their permissions to prevent this, but may use System Integrity Protection (SIP). This has changed in backups made by Big Sur to APFS disks.
To delete all backups on a volume containing no other files, the simplest way is to reformat that volume using Disk Utility. To remove one or more backups but keep the rest of the backup set, do this in the Time Machine app rather than the Finder, or use the tmutil command in Terminal, although that’s complicated. The Time Machine app only lets you do what’s safe, and won’t damage your other backups.
If you can’t put that backup back into its original location, which can be aided by the Put Back command in the Bin, if it’s still available, then it may be simplest to restart from an external disk and then try emptying the Bin. Sometimes even that won’t work, and the only answer is to use the rm command in Terminal. That’s very risky and should only be a last-ditch measure. You’ll need to be absolutely certain that the path is correct, and use the ‘rm -rf path’ command.