Following some discussion on #anaconda this morning I noticed that EL 7 has a bug which was recently fixed for Fedora as https://bugzilla.redhat.com/show_bug.cgi?id=1250260 .
If you boot an EL 7 installer image (I checked the most recent CentOS netinstaller image, but I'm assuming they're all the same), /etc/vconsole.conf is missing. This means that systemd-vconsole-setup will not load any console font; the system firmware console font will be used, and this is likely to not include non-Latin characters.
I believe EL 7's official default console font is still latarcyrheb-sun16 - Fedora changed to eurlatgr in Fedora 22, but I don't think that change has been applied to EL 7. So the commit to fix this on master was:
but for EL 7 it should be adjusted to use 'latarcyrheb-sun16' rather than 'eurlatgr' (the 'eurlatgr' font does not actually exist in current EL 7 images).
This is kinda in the same area as https://bugzilla.redhat.com/show_bug.cgi?id=1182562 , but more general; even though that fix should handle most cases of 'running a text install in a non-Latin language' I think it's still worth doing this in case there are any cases where someone might want to view non-Latin text in the installer environment that aren't covered by that fix. I don't think this would *conflict* with that fix, as that stuff all takes effect long after systemd-vconsole-setup has run.
Note for users hitting this with current EL 7 images: you can force a specific console font with the 'vconsole.font' kernel parameter, e.g. 'vconsole.font=latarcyrheb-sun16'. For a successful text install in Russian, my recipe is this:
inst.lang=ru_RU.UTF-8 inst.text vconsole.font=latarcyrheb-sun16 vconsole.keymap=ru
the 'vconsole.keymap' parameter handles https://bugzilla.redhat.com/show_bug.cgi?id=1265346 .
It looks like kbd-misc needs to add the font before we can do this.
Verified on lorax-19.6.77-1, file /etc/vconsole.conf is available in image.
# cat /etc/vconsole.conf
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.