To begin troubleshooting general problems, examine the log file or files related to the component exhibiting failures. A useful exercise is to tail all log files and then run up2date --list. You should then examine all new log entries for potential clues.
A common issue is full disk space. An almost sure sign of this is the appearance of halted writing in the log files. If logging stopped during a write, such as mid-word, you likely have filled disks. To confirm this, run this command and check the percentages in the Use% column:
In addition to log files, you can obtain valuable information by retrieving the status of your various components. This can be done for the Apache HTTP Server and Squid.
To obtain the status of the Apache HTTP Server, run the command:
service httpd status
To obtain the status of Squid, run the command:
service squid status
If the administrator isn't getting email from the RHN Proxy Server, confirm the correct email addresses have been set for traceback_mail in /etc/rhn/rhn.conf.