How to load ESB Volume by ID via .ebextensions

I'm trying to mount the same volume for a Beanstalk build but can't figure out how to make it work with the volume-id.

I can attach a new volume, and I can attach one based on a snapshot ID but neither are what I'm after.

My current .ebextension

commands:  01umount:    command: "umount /dev/sdh"    ignoreErrors: true  02mkfs:    command: "mkfs -t ext3 /dev/sdh"  03mkdir:    command: "mkdir -p /media/volume1"    ignoreErrors: true  04mount:    command: "mount /dev/sdh /media/volume1"  option_settings:   - namespace: aws:autoscaling:launchconfiguration     option_name: BlockDeviceMappings     value: /dev/sdh=:20

Which of course will mount a new volume, not attach an existing one. Perhaps snapshot is what I want and I just don't understand the terminology here?

I need the same data that was on the volume when the autoscaling kicks in to be on each EC2 instants that scales... A snapshot would surely just be the data that existed at the point the snapshot was created?

Any ideas or better approaches?