GLPI, as any other PHP application is by default limited to the maximum size of the uploaded file of 2MB.
This is because of the factory PHP settings on most Linux distributions and can be easily modified in your php.ini file. You should change these directives, even though upload_max_filesize is directly relevant only:
Make sure to use the correct units, php.ini should be located at:
Once you are done, restart Apache using this command:
If the upload_max_filesize is larger than post_max_size, you must increase post_max_size so that it is bigger than upload_max_size.
If the value of post_max_size is larger than memory_limit, you must increase memory_limit so that it is larger than post_max_size.