Instant Thumbnail Generation
Log into your NAS with PuTTY or another SSH client.
# /usr/local/sbin/ImR_all -soft /Qmultimedia
to start the thumbnail creation, but then PuTTY needs to stay open and your computer needs to be running all the time, otherwise it will stop after a couple of minutes.
To get around this limitation, see Screen command.
Thanks for the contribution from rotwang