Don’t forget those backups

We often like to set and forget routine tasks, such as backing up with Time Machine. But if you decide to start intensive housekeeping – on a large Photos library, for instance – after a while, free space on your backup storage will decline sharply, as every change you’ve made is written out each hour.

Before Big Sur, that wasn’t a problem, as you could delete intermediate files from your backup to recover the space. But now, backing up to APFS, you can’t do that, as deleting whole backups would trash photos of the baby along with clips of the bathwater…

Excluding folders from your backups is adaptive, depending on what you’re doing. It may be better to move projects to a working volume, whose backups can be removed entirely when you’re done. Like your work, your backups need to be dynamic.