Thanks gtJormungand for your reply.
I can't create a Documents folder on/hdd3, it's read only.
if I search for hdd3 in root/etc/rc.d/rc.rofilesys
I get:
##mount -t vfat -o noatime,quiet,umask=000,iocharset=utf8 /dev/${IDE1}3 /hdd3
## mount -t vfat -o noatime,quiet,umask=000,iocharset=utf8 /dev/${IDE1}3 /hdd3
## mount -t vfat -o noatime,quiet,umask=000,iocharset=utf8 /dev/${IDE1}3 /hdd3
do I have to uncomment those lines?
anyway I tried it, because when i manually enter
mount -t vfat -o noatime,quiet,umask=000,iocharset=utf8 /dev/${IDE1}3 /hdd3
I can write to /hdd3
but I can't save a modified rc.rofilesys.
thanks again for your help!