What does "Available", "Attached", and "Unattached" mean in the EBS Volume Report?

Products

• CloudHealth

Issue/Introduction

Under the Volume usage report, the "EBS Volume Status" dimension/filter is based on the volumes current status. 

• If it shows "Available", this means it is currently active but not attached to any instance (unattached) or if it has been deleted and was not attached to an instance at the time it was deleted.
• If it shows "Attached", this means it is current attached to an instance.

The #attached and #unattached y-axis, is at that point in history.  So you can have 1 volume that was unattached on January 1st but is currently attached to an instance the report would show 1 on January 1st with the #unattached y-axis but the categorization for "EBS Volume Status" would be "Attached". 

For a volume that is created, but never attached to an instance, the “Unattached Date” is the “updated_at” time we get from the API.  If that volume is then attached to an instance, the expectation is that the unattached date to clear out.

If an attached volume is then unattached, we get the unattached date from AWS API call, which gives us a status.

If we see a status of “Available”, we set the unattached date to the time that we collected and processed that API call.