I am using blueimp jquery, if I upload a file more than 50 MB, it shows the error : Failed to write file to disk, why is this happening ? My phpinfo settings for post_max_size is 1072. But then its showing this error..

please help me where I have to change this and fix it so that it can allow an upload of min 100 MB at a time ?

php.ini Settings:

post_max_size = 1072M 
upload_max_filesize = 1050M 
memory_limit = 2000M

upload_tmp_dir : this I have set to /tmp once and even commented upload_tmp_dir , either way its showing the error.! Please reply me asap.

Thanks in advance..