SQL Server hangs during backup on EC2
We are having a similar problem when we conduct backups. It looks as though the disk reads are maxing out the EBS connection. 

I think the problem is down to the Throughput limits on an instance type. Check the max bandwidth column here: 

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSOptimized.html

The only solution seems to be switching to a different instance type with more throughput. Have you found any other solutions?