If you’re recently installed WordPress onto a new server (we do this a lot on Amazon EC2 instances of varying sizes) and you notice that your image uploads aren’t auto-thumbnailing (when WordPress “crunches” your images into “thumbnail” “medium” and “large” sizes for use throughout your website) then chances are your server doesn’t have the GD Library installed.
How to Install GD Library on your LAMP Server
On a centos system, the following command in your SSH terminal will install the GD Library:
yum install php-gd
After you’ve hit “y” and the installation has completed, because this is used by PHP scripts, and is therefore loaded when Apache starts, you’ll also need to restart your apache web server using the following command:
service httpd restart
Any problems getting this setup, and leave a comment below. Also feel free to comment if this helps you to get WordPress thumbnails working on your LAMP setup![Note – LAMP stands for Linux Apache MySQL PHP, in case you were wondering]