I am sure I am missing something obvious, but I can't find a way to set the default EBS volume size per layer. Every instance I boot on this layer has a 10GB volume by default.
In the Layer configuration pane I try to add an EBS volume with the size I need, but it won't let me mount it on "/".
I need this extra size for my app installed at /srv/www but the doc says one should not mount a volume at this point:
Do not mount Amazon EBS volumes to the following mount points. If the instance is rebooted, autofs might use them to mount an ephemeral device instead of your volume.
/srv/www
You can't mount volumes at /, that's the root.
Unfortunately you can't set the root device size in OpsWorks.
But you could mount a volume somewhere else like /mnt/www and symlink there.