要改php.ini，基本是改这几项：
max_execution_time = 30
max_input_time = 60
memory_limit = 8M
upload_max_filesize=8m

php.conf发现内容如下：
#
# PHP is an HTML-embedded scripting language which attempts to make it
# easy for developers to write dynamically generated webpages.
#

LoadModule php4_module modules/libphp4.so

AddType application/x-httpd-php php .php3

#
# Cause the PHP interpreter handle files with a .php extension.
#

SetOutputFilter PHP
SetInputFilter PHP
LimitRequestBody 524288


#
# Add index.php to the list of files that will be served as directory
# indexes.
#
DirectoryIndex index.php

看到那个524288吗，换算下就是512k。把它改成52428800，reload apache。经测试，可以上传几十兆的文件，问题解决。