Changing File Upload Size Limits in WordPress Multisite

Just changing the file upload limit in WordPress multisite may not give you the results you desire. Instead it becomes necessary to change the file size limits on your server as well as WordPress can only handle files as big as what your server can handle. Fortunately this is a very easy process. Note that some of the syntax below may change based on your Linux distribution the lines to change in php.ini will be the same regardless.

On your server find and edit your php.ini file. In Ubuntu using suexec and fastcgi use the command:

sudo nano /etc/php5/cgi/php.ini

Next find and edit the following two lines to your desired values:

post_max_size = 8M

and

upload_max_filesize = 20M

In both cases the M stands for megabytes. For example if you want to allow 1 gig file uploads you could, for demonstrations sake make each value 1024M.

Save the file and restart apache. In Ubuntu use the following command

sudo /etc/init.d/apache2 restart

Next, go to your network admin settings and change the Max upload file size box accordingly. Note that while the settings in your php.ini can be larger than your WordPress settings, you cannot set your WordPress settings to a value larger than those in your php.ini.