- `delete_on_termination` (boolean) - Indicates whether the EBS volume is
  deleted on instance termination. Default `false`. **NOTE**: If this
  value is not explicitly set to `true` and volumes are not cleaned up by
  an alternative method, additional volumes will accumulate after every
  build.

- `device_name` (string) - The device name exposed to the instance (for
  example, `/dev/sdh` or `xvdh`). Required for every device in the block
  device mapping.

- `encrypted` (boolean) - Indicates whether or not to encrypt the volume.
  By default, Packer will keep the encryption setting to what it was in
  the source image. Setting `false` will result in an unencrypted device,
  and `true` will result in an encrypted one.

- `iops` (number) - The number of I/O operations per second (IOPS) that
  the volume supports. See the documentation on
  [IOPs](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_EbsBlockDevice.html)
  for more information
