Plesk: 500 – Internal Server Error
Posted by Florian N in Plesk, tags: 500 - internal server error, apc_mmap, No space left on device, PleskThe easiest way to check for what the issue is(as there could be a few different problems when seeing this error) is to check the Plesk log file which is located under : /var/log/sw-cp-server/error_log .
In my case the issue was related to the apc_mmap module which was reporting “No space left on device”, here is the full error:
[Tue Jan 19 17:01:21 2010] [apc-error] apc_mmap: mmap failed: No space left on device
2010-01-19 17:01:21: (mod_fastcgi.c.1000) the fastcgi-backend /usr/bin/sw-engine-cgi -c /opt/psa/admin/conf/php.ini -d auto_prepend_file=auth.php3 -u psaadm failed to start:
2010-01-19 17:01:21: (mod_fastcgi.c.1004) child exited with status 2 /usr/bin/sw-engine-cgi -c /opt/psa/admin/conf/php.ini -d auto_prepend_file=auth.php3 -u psaadm
2010-01-19 17:01:21: (mod_fastcgi.c.1007) if you try do run PHP as FastCGI backend make sure you use the FastCGI enabled version.
You can find out if it is the right one by executing 'php -v' and it should display '(cgi-fcgi)' in the output, NOT (cgi) NOR (cli)
For more information check http://www.lighttpd.net/documentation/fastcgi.html#preparing-php-as-a-fastcgi-program
2010-01-19 17:01:21: (mod_fastcgi.c.1012) If this is PHP on Gentoo add fastcgi to the USE flags
2010-01-19 17:01:21: (mod_fastcgi.c.1105) [ERROR]: spawning fcgi failed.
An easy fix for this would be to modify the php.ini file for Plesk and take out the apc_mmap module.
The php.ini file that serves Plesk is located under /opt/psa/admin/conf/php.ini or /usr/local/psa/admin/conf/php.ini .
Just open the file with an editor(vi, nano) and comment the following lines:
apc.stat = 0
apc.shm_size = 40
apc.include_once_override = 1
Once done just restart Plesk and check you login URL as this issue should be fixed.
Like i said please check the error log file as the issue may be a bit different even though the error will still be reported as “500 – Internal Server Error”.

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thank you thank you thank you
I have the same problem but in windows server 2008
Thank you, thank you, thank you.
Had this problem for the first time today. Edited the php.ini file and did the restart. Everything fine again.
Thank you.