Thank you very much Till and Falko.
When falko mentioned vhost file then i decided to check other things apart from just upload limit configuration.
Then i decided to run this command to see if php package am using is properly compiled with fast cgi. Coz i started to think that may be fast-cgi is not working properly.
Then i run this command:
Then i got what i was looking for with addition of the following ERROR msg
PHP: Error parsing /etc/php5/cgi/php.ini on line 222
Since vi doesn't show line numbers by default, i enabled line numbers with the following command. :set nu
After reaching that line i remembered that i did some security issues on the server before, but i made some errors on disable_functions
disable_functions = disable_functions = show_source, system, shell_exec, passthru, exec, phpinfo, popen, escapeshellarg, escapeshellcmd, proc_open
disable_functions = show_source, system, shell_exec, passthru, exec, phpinfo, popen, escapeshellarg, escapeshellcmd, proc_open
note on the first part disable_functions
Hope this will help someone else facing the same problem.