Image Cache Problem Magento - Server Related

I have a linux server with a Magento store installed. Everything works fine except the image cache wont generate. The images are available in the backend. And also show in the media folder, but not in the media cache folder. The required cache folders generate, like media/catalog/product/cache/1/image/1800x/040ec09b1e35df139433887a97daa66f/images/catalog/product/placeholder But there are no images inside and its 404 for the images on the frontend. I already tried setting permissions to 777, edit the htaccess file, all the standard stuff suggested in Google. The only thing I can think of is its a group/user permissions but the folder shows as being owned by this user group/user. Im out of ideas, but I think its most likely related to some server configuration. If you dont know linux server config stuff, dont bid please. Thanks