Comment 1 for bug 2060098

As noted, Juju doesn't support this. You're right that we *could* support mounting the EBS volume on the host, and then work throug the mechanics to provide it to LXD, and get it mounted into a container.
We don't have any of that logic today, and it is not exactly trivial to get right, especially with edge cases around when storage shows up, how to do clean setup/teardown/etc.

In general, we haven't prioritized this work because when you are deploying into clouds, you already can size VMs however much you would like, so there isn't much *need* to take a VM and then carve it up into LXD containers.
(Note that you also will have a host of issues around networking and accessibility, etc, so storage is only one of the concerns around containers inside of VMs on arbitrary clouds.)

If there are hard constraints as to why things need to be spun up into containers-inside-VMs, you're welcome to raise it as a request, but you are definitely in "this has never been supported, so cannot be considered a bug" territory.