Thanks. For completeness what I did for now: # vnconfig vnd0 install66.iso # mount -t cd9660 /dev/vnd0c cd/ # cp -r cd cd2
# cp bsd-mod.rd cd2/6.6/amd64/bsd.rd # cp site66.tgz cd2/6.6/amd64/
# mkhybrid -a -R -T -L -l -d -D -N -o install66a.iso -vv -A "Unofficial OpenBSD 6.6 amd64 autoinstall CD" -P "Copyright (c) 2019 Theo de Raadt, The OpenBSD project" -p "Thomas Bohl <f...@example.com>" -V "Unofficial OpenBSD/amd64 6.6 CD" -b 6.6/amd64/cdbr -c 6.6/amd64/boot.catalog cd2
