Nginx + PHP-FPM Error: This Page is Temporarily Unavailble

[ragebflame]

Ok, so I have had a look through the docs and the readme.

The error that I am getting when I try to access /admin is now:
create_pagesxml: unable to open /var/www/cms/data/pages/

I thought this may have been a permissions issue so I set the permissions using:

sudo chmod -R 0775 /var/www/cms

I am still getting the same error however.