Is the advice to use snapshots to save money so as not to run too many droplets, not actually possible?

Hi there! Hmm for rebuilds, you should be able to use “any image in your account that runs an OS that is in the same family as the Droplet you’re rebuilding, including backups, snapshots, custom images, 1-Click Applications, and base OS distributions we provide.” This is directly from the doc I linked previously.

If D1 and D2 are both Ubuntu, you should be able to rebuild either with a Snapshot taken of either Droplet. I’m happy to take a closer look at this in a Support ticket if you’d like! There may be other limitations such as the regions the Snapshot is available in.

I noticed this just now by attempting to rebuild an Ubuntu 16.04 Droplet from an image I just created from an Ubuntu 18.04 Droplet. Because my 16.04 Droplet is in the NYC1 region and my 18.04 Droplet is in NYC3, the Snapshot did not display in the rebuild image options. When I made the 18.04 Snapshot available in both regions, it successfully appears in the rebuild image options.

How to Add Droplet Snapshots to Other Regions https://www.digitalocean.com/docs/images/snapshots/how-to/change-regions/z

I agree with you that my terminology was not quite correct though, I should have said any “image” rather than “Snapshot,” thanks for pointing that out! Using Snapshot as a term for both base OS image and custom created image is confusing and not accurate. I’ll keep this in mind to be more consistent in the future :)

Are you able to create a Droplet from that Snapshot image? https://www.digitalocean.com/docs/images/snapshots/how-to/create-and-restore-droplets/#create-new-droplets-from-a-snapshot

Restoring requires an active Droplet, and you are replacing the current image on that existing Droplet with a Snapshot.