ServerBuddies Support Blog

Separating standard output from standard error

Constructs like these are often used by programmers, so that output is displayed in one terminal window, and errors in another. Find out which pseudo terminal you are using issuing the tty command first:

To find the tty type

When compiling receive the error et/com_err.h: No such file or directory

If you receive the error When compiling.

Then install the following to resolve.

or

Source : http://directadmin.com/

Internal Server Error with cgi files

This means that the cgi script did not execute properly. There are several causes that can generate this error so a few things would need to be checked.

1) check the /var/log/httpd/suexec_log. It contains any errors that would be as a result of not having correct permissions on the file.

2) The file needs to be in a cgi-bin and must have the owner/group as the username who owns the site.

3) The script must have execute permission.

4) The most common chmod permission is 755.

5) The easiest way to figure out script coding problems is to first run the script manually from an ssh prompt.

6) Other errors that would be generated when running the script manually from ssh would be missing perl modules.

7) Cpan is the easiest method to install new perl modules, eg:

MySQL Error Log File

The error log contains information indicating when mysqld was started and stopped and also any critical errors that occur while the server is running.

If mysqld notices a table that needs to be automatically checked or repaired, it writes a message to the error log.
On some operating systems, the error log contains a stack trace if mysqld dies.

You can specify where mysqld writes the error log with the –log-error[=file_name] option.
If no file_name value is given, mysqld uses the name host_name.err by default and writes the file in the data directory.

On Windows, error output is always written to the .err file if –console is not given.

If you use mysqld_safe to start mysqld, mysqld_safe arranges for mysqld to write error messages to a log file or to syslog mysqld_safe has three error-logging options, –syslog, –skip-syslog, and –log-error.

Permission denied error, while executing Nagios binaries

Nagios provides enterprise-class Open Source monitoring of hosts and services.

Make sure that the Nagios user has correct ownership/permissions to Nagios files in the Nagios installation directory.

Check if SElinux is enabled. If it is enabled, the Nagios binaries won’t be executed.

There are 3 alternative solutions for this.

1) Disable SElinux, SELINUX=disable.

2) Make it execute non-built-in services like Nagios by setting, SELINUX=permissive. This would cause the binaries to execute with only warnings logged to /var/log/messages.

If you go for the fix 1 or 2, you would need to reboot the server once.

3) You can change the security context of the Nagios binaries and make them executable with SElinux enabled.