How do I know the space (in GB) used by a "Snapshot"?

Hi there,
Thanks for using Lightsail,

The initial snapshot is a replica of the resource. In your example, the initial snapshot of a 40-GB instance would be 40 GB in size. However, subsequent snapshots are incremental, which means, only the difference between the previous snapshot and the current state will be saved, this minimizes time and storage.

You can find more details in our documentation for snapshots: https://lightsail.aws.amazon.com/ls/docs/en_us/articles/understanding-instance-snapshots-in-amazon-lightsail

I hope that helps, let us know if you have more questions.

Regards,
Rafael

Understand the initial snapshot is a replica but if the disk is largely empty - would the charge really be for the full disk (60gb in this instance) ??? That seems not so fair - for example a fresh install really should be minimal size right?

Also for the successive snapshots being incremental in size; how can I see the actual size of the incremental snapshots (ie how much I will be charged)