Am 2020-06-14 20:07, schrieb dng@???:
> It is a kernel parameter not a module parameter. You have to add it to
> your kernel boot line.

Ok, I found out how to do that. It's in /boot/boot.ini
But that made no difference to my problem.

This is my current setup:
/etc/fstab has the mount option nofail, so the boot does not hang on
mountall.

I have a additional init script mounthdd:

# Provides:          hdd
...
if mountpoint -q /hdd
then
   echo 'HDD is already mounted'
else
   echo 'HHD is not mounted'
   mount /hdd
   /usr/local/bin/wait4hdd
fi

and the wait4hdd script:

#!/bin/sh
while ! mountpoint -q /hdd
do
echo "Waiting for hdd"
sleep 10
mount /hdd
done

Now the following messages in /var/log/boot:

Thu Jan 1 01:00:18 1970: HHD is not mounted
Thu Jan 1 01:00:18 1970: Waiting for hdd
Sun Jun 14 20:19:24 2020: Waiting for hdd

Success after several tries.