How to clear data in PostgreSQL tables to free up disk space?

Question

PostgreSQL

Good day!
The situation is this: there is a database (psql), which in a month swells up to 100GB, due to the large amount of data (for a month in total about 1 billion rows in tables). Hard disk space is limited. After the database gobbled up all the free space, I couldn’t do something with it - the psql service does not start, but by deleting something from the data folder (there is no free space on the machine and nothing can be deleted except the database) - the base is not restored. But that's not the point. How can I clean up data in tables for a certain period with REAL freeing up disk space? The fact is that I performed a DELETE for all tables, deleting records older than a week (before that there were records for 3 weeks), after which I performed a VACUUM for the entire database. After these very long operations, -500Mb was released. It is with a minus sign. ABSOLUTELY NOTHING was released, quite the contrary.
PS: I used to work with Microsoft SQL, I never encountered such problems there...

Answer 1

The first link in Google leading to the documentation:
Further, a more preferable alternative to VACUUM FULL: habrahabr.ru/post/169939

Answer 2

It is worth doing a full vacuum, but again it requires a lot of space, that is, if there is no space left at all, then it will not be able to pass normally.
It is logical to copy-paste the database to another server where there are no problems with the place.