On 06/21/2017 04:44 PM, Ignazio Cassano wrote: > * Connection #0 to host cloud-images.ubuntu.com left intact > Downloaded and cached > http://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-root.tar.gz, > having forced upstream caches to revalidate > xenial-server-cloudimg-amd64-root.tar.gz: FAILED > sha256sum: WARNING: 1 computed checksum did NOT match > Are there any problems on http://cloud-images.ubuntu.com ? There was [1] which is apparently fixed. As Paul mentioned, the -minimal builds take a different approach and build the image from debootstrap, rather than modifying the upstream image. They are generally well tested just as a side-effect of infra relying on them daily. You can use DIB_DISTRIBUTION_MIRROR to set that to a local mirror and eliminate another source of instability (however, that leaves the mirror in the final image ... a known issue. Contributions welcome :) -i [1] https://bugs.launchpad.net/cloud-images/+bug/1699396