OK, We believe this is related to deploying in simple mode where curtin formats the root filesystem and label's it 'cloudimg-rootfs' which matches the /etc/fstab entry in the ephemeral environment; subsequently, systemd's fstab generator creates a mount unit for "cloudimg-rootfs" to be mounted at /media/root-ro; This races with curtin's attempt to wipe the device. To confirm, this should reproduce 100% if you deploy with no custom storage config, followed by a custom config. Also, it would be interesting to see if that also reproduces with Xenial in the above scenario; that may help narrow down changes to systemd that make this more likely in zesty. On Thu, Apr 6, 2017 at 10:18 AM, Ryan Harper