virtualName

The virtual device name ( ephemeral N). The name must be in the form ephemeral X where X is a number starting from zero (0). For example, an instance type with 2 available instance store volumes can specify mappings for ephemeral0 and ephemeral1 . The number of available instance store volumes depends on the instance type. After you connect to the instance, you must mount the volume. NVMe instance store volumes are automatically enumerated and assigned a device name. Including them in your block device mapping has no effect. Constraints : For M3 instances, you must specify instance store volumes in the block device mapping for the instance. When you launch an M3 instance, we ignore any instance store volumes specified in the block device mapping for the AMI.

After the instance is running, modifying this parameter results in instance replacement .