Why aren't my droplets having their disks resized? (API)

I’m running an application which needs to be able to spin up droplets of different sizes, and I’m a bit puzzled about why my disk sizes appear not to be updating.

The script involved waits until the droplet is powered off, then triggers the resize API query like the following curl example:

curl -X POST -H ‘Content-Type: application/json’ -H “AUthorization: Bearer <token>” -d ‘{“type”:“resize”, “size”:“8gb”}’ “https://api.digitalocean.com/v2/droplets/<dropletID>/actions”

I get responses like the following:

{“action”:{“id”:296405318,“status”:“in-progress”,“type”:“resize”,“started_at”:“2017-09-26T18:31:17Z”,“completed_at”:null,“resource_id”:63894287,“resource_type”:“droplet”,“region”:{“name”:“New York 3”,“slug”:“nyc3”,“sizes”:[“512mb”,“1gb”,“2gb”,“c-2”,“4gb”,“c-4”,“8gb”,“c-8”,“16gb”,“m-16gb”,“c-16”,“32gb”,“m-32gb”,“48gb”,“c-32”,“m-64gb”,“64gb”,“m-128gb”,“m-224gb”],“features”:[“private_networking”,“backups”,“ipv6”,“metadata”,“install_agent”],“available”:true},“region_slug”:“nyc3”}}

The resize succeeds, and I get an 8GB node with 4 cores and 8 GB of ram, but I’m still getting 20GB of hard disk space. The size list documentation (linked below) seems to indicate that I should be getting 80 GB.

What’s up?

Thanks, -Grant