Is there a way to cancel the creation of a snapshot?

It has been running for almost 48 hours now. Automated backups are not being created because it is busy with this marathon manual backup.

How big is the database? If it is tens or hundreds of GB then I wouldn't expect taking the snapshot to be a multi-day affair. If it is several TB, then I can imagine scenarios where it could take a long time. The forums are for community discussion, not technical support, and AWS personnel only participate intermittently. You generally need to open a support case to get help with something like this.

AFAIK there is no way to cancel a snapshot in progress. Although the underlying EBS snapshot(s) can be deleted while being taken, EBS actually continues creating the snapshot until it completes. The in-process, though deleted, snapshot counts against the maximum number of concurrent snapshots limit, and perhaps has other behavioral implications as well. This may be why RDS doesn't allow its snapshot workflow to be interrupted (i.e., by allowing a snapshot delete or another way to express "cancel"), as it could lead to inexplicable failures later on. Even that might be historical in nature, and more reasonably handled today then when the workflow was originally designed and written. So certainly worth a feature request to allow snapshots to be deleted/canceled while in process.

It is only 50GB but it has since completed. It took 51 hours. Thanks for the info though.

That is very odd, but glad it finished