How to use tmutil delete on Big Sur, APFS I'm using macOS 11 Big Sur and APFS. I sometimes want to remove old backups to save space. I don't want Time Machine taking up the entire external drive.
% tmutil listbackups
2020-10-18-001052.backup
2020-11-06-124150.backup
2020-11-15-173211.backup

% sudo tmutil delete 2020-10-18-001052.backup
Total deleted: Zero KB

I think I have to pass a &quot;path&quot; to tmutil delete. How do I get the path? Or how do I otherwise delete one of the backups listed by tmutil listbackups?
The Big Sur syntax changed, but you need to specify the volume and the timestamp with -d and -t:
sudo tmutil delete -d /Volumes/Time\ Machine -t 2020-11-18-100936

You don't need to specify the Backups.backupdb folder or the backup machine.  I had done tmutil setdestination /Volumes/Time\ Machine previously (where Time Machine is the name of your drive.)