

Apt v3 comes with some quality-of-life stuff that apt has been direly missing for years, and one of those is apt sources that make sense to a human.
So the new apt source files have local key location, components, suites, and Uris.
The sources from the before-time just had a one-liner with a uri and some components.
Edit:also the modernize command makes a backup of the source files it touches.

Migrated my storage from an old xeon-d to an arm SBC w 4GB ram and a sata hat. Performance is great, ZFS keeps up with all tasks, and less than a third of the power consumed. Backup scripts are running nightly without issue.
I am continually astounded by how well ZFS performs, even 15 years after I starting working with it. 4GB is enough for a mirror.