Set the fastest mirror from preseed

So, choosing the best mirror in the /etc/apt/sources.list can be simply done by removing the country prefix before "archive.ubuntu.com" (i.e. "us.").

For a new installation, it should be possible to specify this instruction on the preseed file:

d-i mirror/http/mirror select archive.ubuntu.com

But for some reason, the installer ignores this line and keeps the prefix as the ISO-3166-2 country code, from the locale settings. This is not so optimum for standard installations with "us" locales connecting from somewhere else than US.

Is this a bug, or am I doing something wrong? (I'm using Ubuntu server 16.04)

You might be able to get away with simply adding a mirror hostname:

d-i mirror/http/hostname string archive.ubuntu.com

I've been using the following mirror settings for a test preseed for a while, and it seems to work well enough for my purposes:

d-i mirror/country string manual
d-i mirror/http/hostname string mirrors.us.kernel.org
d-i mirror/http/mirror select mirrors.us.kernel.org
d-i mirror/http/directory string /ubuntu
d-i mirror/http/proxy string