Block Device Mapping?

[robksawyer]

What's this actually used for?

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html

def script(opts, conf):
    itype = brenda_instance_type(opts, conf)
    snapshots = aws.get_snapshots(conf)
    bdm, snap_description, istore_dev = aws.blk_dev_map(opts, conf, itype, snapshots)
    script = startup_script(opts, conf, istore_dev)
    print script

in run.py of the brenda script