Today I needed to increase the file upload limit in a WordPress multi-site + BuddyPress installation. The limit was set by php.ini on the server, so there was no way to increase the limit within WordPress.
The solution is a bit complex if you are a command line noob like me, and it does require a basic understanding of command line stuff as well as root access to your server. That said, with some guidance from someone like Dave, you can be rolling on the command line in no time!
Step 1: SSH into your website root via Terminal (on Mac) or your command line tool of choice.
Step 2: Find your php.ini file by typing something like this – grep -i php.ini
Step 3: Make sure you are in the same directory as your php.ini file and then edit your php.ini file by typing nano php.ini
Step 4: Edit the upload_max_filesize, post_max_size, and memory_limit properties in your php.ini file
Step 5: Save php.ini by exiting Nano
Step 6: Restart Apache by typing the following into Terminal: /etc/init.d/httpd restart
Many thanks to Dave for his help!