Add user nobody, the installation need this user in the system.

adduser nobody

Update and upgrade ipkg

ipkg update && ipkg upgrade

Install

ipkg install dokuwiki && ipkg install php-iconv

Create symbolic linke inside /share/MD0_DATA/Web to dokuwiki installed directory

ln -s /opt/share/www/dokuwiki/ /share/MD0_DATA/Web/dokuwiki

Change owner of files

chown -R httpdusr /opt/share/www/dokuwiki

Upgrade dokuwiki

# cd /tmp
# wget http://www.splitbrain.org/_media/projects/dokuwiki/dokuwiki-2012-10-13.tgz
# cd /opt/share/www
# mv dokuwiki dokuwiki.orig
# tar -xpf /tmp/dokuwiki-2012-10-13.tgz
# mv dokuwiki-2012-10-13 dokuwiki
# chown -R httpusr dokuwiki

Connect to QNAP and configure, eg:

http://qnap.local/dokuwiki/install.php

Once configured disable install.php

cd /opt/share/www/dokuwiki
chmod 000 install.php