Thanks for your help! It finally works now!   Turns out that "normalizeInstance" has to set to true. It's a bit confusing though as in the comment it says the following and I thought most of them are already done in the preloaded AMI. # Normalization includes: # downloading and installing packages # minimizing swappiness # increasing the maximun number of open files # mounting ephemeral disks # resizing the root partition. I will modify the packer scripts to download additional parcels we need. It will be great if you add support semi-preloeaded AMI so small parcels can be downloaded during provisioning. ... View more