The raw image will be expanded to fill the disk at installation time.
The raw image is
self-installing: it only carries the EFI
and recovery partitions, and the root (
SYSTEM)
partition is created on first boot from whatever space is left on
the disk it booted from. So there is no point writing tens of GB of
zeros at build time, and all the extra space lands in
/
either way.
This wizard only hands out the config, so you run elemental
yourself — which is why the size above defaults small. Convert the image
to qcow2 to save some space then grow it
before its first boot.
This will save space on your hypervisor and the copy will be faster.
elemental customize only
emits raw, there is no
--type qcow2:
qemu-img convert -f raw -O qcow2 image-<timestamp>.raw disk.qcow2
qemu-img resize disk.qcow2 100G
What you must not do is
boot it at 8 GB: an ~8 GB root has
no room for the RKE2, Rancher, storage and AI Factory container
images, let alone model weights. Whatever the disk measures at
first boot is what you are stuck with, and below ~100 GB you should
expect a full disk and a cluster that never converges.