I spent days getting this to work - omsc running on Raspi 2 with Network Hard drive connected to Netgear router no passwords on hard drives.
This worked to manually mount
sudo mount -t cifs -o user=<youruser>,password=<yourpassword>,sec=ntlmv2 //192.168.1.3/USB_Storage/recordedtv /home/osmc/recordedtv
to get to auto mount on boot using etc/fstab add following line to fstab
//192.168.1.3/USB_Storage/recordedtv /home/osmc/recordedtv cifs user=<yourusername>,password=<yourpassword>,sec=ntlmv2 0 0
Add to etc/rc.local this waits for network (tried _netdev didn't work for me)
sleep20
sudo mount -a
Hope this saves someone else days of frustration. :-)