This is the way how it could be made use of:

8<--------------------------------------------------------------
FAI_PROGRESS_VT=$(openvt -v 2>&1 -- sh -c "
        export TERM=linux ;
        export TERM_UTF8=yes ;
        export FAI_LOG_PATH=$LOGDIR/fai.log ;
	[ -f /etc/default/locale ] && eval $(echo -n "export "; grep ^LANG /etc/default/locale) ;

        if [ -c /dev/fb0 ]; then
                export DEBIAN_FRONTEND=gtk ;
        else
                export DEBIAN_FRONTEND=newt ;
        fi ;

        setterm -blank 0 -powersave off -powerdown 0 ;
        echo -ne "\033%G" ;
        touch -f $FAI_LOG_PATH ;
        /usr/lib/cdebconf/debconf /usr/bin/fai-progress ;
        reset")

FAI_PROGRESS_VT=${FAI_PROGRESS_VT##* }
echo "${FAI_PROGRESS_VT##/dev/tty}" > $LOGDIR/fai-progress-vt  

chvt ${FAI_PROGRESS_VT##/dev/tty}
8<--------------------------------------------------------------


Switch it off:

echo "fai-progress: hangup" >> /var/log/fai.log



