1. List all snapshots for specific volume:
aws ec2 describe-snapshots --filters "Name=volume-id, Values=vol-xxxxxx"
2. If in progress, you can check following for status after getting snapshot-id at step 1:
aws ec2 describe-snapshots --snapshot-id snap-xxxx
You shall get something like the below:
...
"VolumeId": "vol-xxxxx",
"State": "pending",
"VolumeSize": 900,
"StartTime": "2019-06-30T21:26:16.662Z",
"Progress": "46%",
"OwnerId": "xxxx",
"SnapshotId": "snap-xxxxx"
...
