Change PHP Upload Size

To change the PHP maximum upload size, you need to edit the php.ini file and then restart the webserver.

Depending on your Linux distribution, the php.ini will be located at a different location:
CentOS / Red Hat: /etc/php.ini
Ubuntu / Debian: /etc/php/your_version/apache2/php.ini

You need to change two parameters: upload_max_filesize and post_max_size. The following setup will allow you to upload files up to 20MB:

upload_max_filesize = 20M
post_max_size = 20M

After saving the file, restart the web server:

sudo service apache2 restart