AWS EBS Multi-Attach
EBS multi-attach is available for specific EBS Volumes (Only for Io1 and Io2 family) and provides a way to attach a single EBS volume to multiple EC2 instances in the same Availability Zone.
Each EC2 instance needs to be able to have full read and write permissions to the attached EBS volume.
The use case for EBS Multi-Attach is very specific such as providing higher availability within a clustered Linux application such as Teradata.
The application must be able to write concurrently into the same EBS volume so the file system must be cluster aware.