If the Apache error log file does not contain enough information, you can modify the log level and the types of messages written to the file.
WARNING:If you set the log level to debug, the size of the file can grow quickly, consume all available disk space, and crash the system. If you change the log level, you need to carefully monitor available disk space and the size of the error log file.
To modify what is written to the Apache error log file, perform the following steps:
Modify the httpd.conf file.
For information about how to modify a file, see Modifying Configurations.
Find the LogLevel directive and set it to one of the following:
debug, info, notice, warn, error, crit, alert, emerg
(Optional) If you set the level to debug and the log file still does not supply enough information, see Section 33.2.5, Enabling Debug Mode and Core Dumps.