Comment 1 for bug 1777149

It's the same or at least similar on VMs: "could not find any partitions"
Proceeding to the d-i shell:

# lszdev --online
TYPE ID ON PERS NAMES
dasd-eckd 0.0.0200 yes no dasda
dasd-eckd 0.0.0300 yes no dasdb
dasd-eckd 0.0.0400 yes no dasdc

But partitions do exist:

# fdasd -ps /dev/dasda
/dev/dasda1 2 150238 150237 1 Linux native
                150239 150239 1 unused
# fdasd -ps /dev/dasdb
                     2 150239 150238 unused
# fdasd -ps /dev/dasdc
/dev/dasdc1 2 450748 450747 1 Linux native
                450749 450749 1 unused

Getting the "not supported" msg on that system:

cat /sys/bus/ccw/devices/0.0.0200/host_access_count
cat: read error: Operation not supported