So this m3.medium ec2 instance that packer has created to build an ami, i selected 'amazon-instance' as the type, and the ubuntu trusty source ami of type "instance-store" (as opposed to ebs, ebs-ssd, ebs-io1, and the hvm:* ones) ... it has / on xvda1 - is this ebs? How would i tell which is local ssd? m3.medium is supposed to have 1 x 4GB SSD volume, which would tend to indicate xvdb is SSD.
df
ubuntu@ip-10-61-150-2:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 9.9G 6.9G 2.5G 74% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
udev 1.9G 12K 1.9G 1% /dev