Azure doesn't like Dynamic VHDs
As discovered in tiny-cloud#51 (closed) and #148 (closed), the VHD we provide for download is not immediately importable into Azure because it's a Dynamic VHD and not a Fixed VHD.
To convert from dynamic to fixed...
qemu-img convert -f vpc -o subformat=fixed,force_size -O vpc \
azure_alpine-3.19.0-x86_64-uefi-tiny-r0.vhd \
azure_alpine-3.19.0-x86_64-uefi-tiny-r0_fixed.vhd
...however this results in a full-size 1 GiB image, which would take up ~10x more space than the dynamic VHD.
I think the answer here is to...
- convert the locally-build QCOW2 to a Fixed VHD for Azure
- compress the resulting VHD
We may want to consider compression for all downloadable images.