This situation only occurs in PHP running in fcgid mode, Maxrequestlen parameter settings are too small. But I also installed, never encountered this situation ah? And I have not set Maxrequestlen, according to the truth he will remain the default value.
So hold not to find the problem reason not to rest, find the relevant parameter data. So to the Apache official station to see the data, originally from the Apache 2.3.6, the default value of this parameter from the previous 1GB (Khan one) adjusted to 131072 bytes (128KB). Then upload 128KB below the file will not be a problem, but over this value will be reported 500 error. Originally I used the OS is usually Ubuntu server 10.04 LTS, and this new installed server with Ubuntu server 12.04 LTS, seems to be the problem, the Apache version of 12.04 is newer, The default value of this parameter was changed to 128KB, which caused the upload file to fail, and reported 500 errors.
Once you find out why, the solution is simple. Only the configuration of this parameter needs to be added.
Open Ubuntu's fcgid configuration file for Apache:
#vim/etc/apache2/mods-enabled/fcgid.conf
Add the following parameter settings to this file. I set this to 10M, than PHP upload maximum 8M slightly larger. You can adjust the value of this parameter according to your own needs, and note that the unit of this parameter is byte.
Maxrequestlen 10240000
Save exit, restart Apache:
#/etc/init.d/apache2 restart
Test again and solve the problem.
We can also refer to this method: Http://www.111cn.net/wy/CMS/45329.htm