Category Archives: Control Panels

Control Panels i work with, what i know and still learn about them

Plesk: 500 – Internal Server Error

The 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
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”.


Plesk install on Ubuntu server – “It seems there is a user with UID=110 in this system” error

Installing Plesk on a Ubuntu or Debian server this days seems to end up with some issues in some cases were the base OS has some extra packages added to it.

Plesk is using hardcoded UID’s for it’s install so if there is a user on the system that already uses the UID needed for one of the users Plesk needs to put in place will cause the install to crash/stop/abort with an error like:

E: Sub-process /usr/bin/dpkg returned an error code (1)
ERROR: An error occurred on attempt to install packages. Attention! Your software might be inoperable

The full snippet of the error looks like this for Plesk Panel 9.0.1 on an Ubuntu 8.04 server:
Errors were encountered while procesing:
/var/cache/apt/archives/plesk-base 9.0.1-ubuntu8.04.build90090127.18.i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
ERROR: An error occurred on attempt to install packages. Attention! Your software might be inoperable

One of the issues is that you don’t see the main reason for this error directly so to exactly catch the problem and see the actual error and why the install crashes/stops one thing you could try is to install the Plesk package directly like:

dpkg -i /var/cache/apt/archives/plesk-base 9.0.1-ubuntu8.04.build90090127.18.i386.deb

After running the last command your install may stop and error out but at least it will show you were the problem is, the error i am speaking in this post will be:

ERROR: It seems there is a user with UID=110 in this system, but Plesk needs the same UID for its operating. Unfortunately, this situation has not yet been resolved.


A small tweak will be needed if you want to get over this issue and that would be to check and edit the /etc/passwd file and change the UID for the user that uses the UID needed by Plesk, in this case 110.
In my install the UID=110 was attributed to the identd user so i had to change that but you have to make sure this UID is not used by any other user already existing on the server.

What i did was changing the UID for the identd user from 110 to 111(in my case this one was not used) and then start the install again.
Guess what, the install finished just fine and Plesk got installed with no issue.

Hope this helps!


Cpanel IMAP error under FreeBSD

This error has been observed mostly on BSD servers even on brand new installs .

It is even that the IMAP server under Courier is not starting at all or the Authentication daemon is throwing out errors.

One of the errors can be seen when trying to access Squirrelmail or Horde, it is even you can not login or get an error like:

Warning: fsockopen() [function.fsockopen]: unable to connect to localhost:143 (Connection refused) in /usr/local/cpanel/base/3rdparty/squirrelmail/plugins/login_auth/functions.php on line 129

If you use the Current version of Cpanel you may want to check firstly if IMAP is actually set to Start or not.
You can check this under WHM >> Service Configuration >> IMAP Coonfiguration .
Under cPanel 11.24.x it is now called Mailserver Configuration .

If this is set to On and you still have issues then try and check the /etc/rc.conf file(FreeBSD) .

Regarding IMAP and the authentication daemon you should see the following lines in there:


If you do not see any of this lines or any of them is looking different edit /etc/rc.conf and edit the line to look like the ones i’ve posted.