0ce40265_Class___CodeIgniter_User_Guide__Description
[Preference] max_size [Default Value] 0 [Options] None [Description] 
The maximum size (in kilobytes) that the file can be. Set to zero for no limit. Note: Most PHP installations have their own limit, as specified in the php.ini file. Usually 2 MB (or 2048 KB) by default.
File Uploading Class : CodeIgniter User Guide
Description