Your starting point will be https://xcp-ng.org/docs/develprocess.html#local-rpm-build
@olivierlambert I've dug into the issue a bit more, and it just gets stranger.
Downloading to my Macbook on the same network gets ~4MB/s. This means there is something strange going on with the control domain around remote downloads.
When I test the disk speed (which is an Samsung NVMe), the speed is 1.7GB/s:
When I test the network speed with Ookla's speedtest-cli it confirms a 1G connection, and a 1G transit to Europe (checked this twice because 1G Atlantic transits are rare):
On my Macbook (on 802.11ac) I can download an Ubuntu image at ~14MB/s
However on the control domain the download speed is considerably lower:
Have you ever see something like this before?
I saw you had some discussion on another thread regarding slow writes in a VM, but this looks like it affects the control domain as well: