このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語)：
unable to delete snapshot
対処
関連リンク
Unable to delete snapshot in AWS | Simplilearn - Discussions on ...
http://community.simplilearn.com/threads/unable-to-delete-snapshot-in-aws.40016/
AWS-Automated-Daily-Instance-AMI-Snapshots/handler.py at master ...
https://github.com/AndrewFarley/AWS-Automated-Daily-Instance-AMI-Snapshots/blob/master/handler.py
GitHub - alestic/ec2-expire-snapshots: Delete expired EBS snapshots ...
https://github.com/alestic/ec2-expire-snapshots
3.4.1 timeouts with 1.7.5 ・ Issue #582 ・ elastic/curator ・ GitHub
https://github.com/elastic/curator/issues/582
Source Record Storage Module - Amazon S3
https://s3.amazonaws.com/foliodocs/api/mod-source-record-storage/p/source-record-storage.html