For the smallest DigitalOcean instance, backups are eating quite a lot - with 7 days backup, I give up 50% of the space just for backups.
Yet I’d still like to have old backups.
The proposition is to make backup frequency configurable. I’d set it to once every 2 days (instead of once every day by default) and save another few GBs - this would free more space for uploads and save me from upgrading my DO instance for another 3-5 months, so literally it would save some $$$.
Not a bad idea, @zogstrip what do you think? It is one more site setting but it might be easy and useful.
Even better – albeit a lot more effort – would be a (configurable) staged setting, like this: Do hourly backups, but keep only two of them; in addition, keep one per day for five days, and a weekly backup for a month.
Simply making the interval configurable would at least make it easier to simulate this with external backup software: Let Discourse take hourly backups (keep only one or two), and backup the backup directory with an external software that offers more flexibility.
I changed the backup_daily? site setting to the more generic backup_frequency 
https://github.com/discourse/discourse/commit/15418f3d44df7c248ebdb1239092e0aa676b3947