• Knowledge Base: Understanding your private server

    1. System Monitoring (Internal)
    2. Mail Server operation.
    1. System Monitoring (Internal) - Top

    All the servers are equiped with a program we have designed call systemcheck which is executed every minute. During execution it takes a picture of the results given when a "ps auxwww" is excuted. The ps script on the server shows which processes are running and what type of resources there using. Systemcheck will anaylize the data to see if all the key system services are running. The services it monitors includes:

    • httpd
    • ocwhttpd
    • proftp
    • sshd
    • sendmail
    • syslog
    • poprelay
    • server load
    • memory
    • diskspace
    • realaudio if installed
    • bind if installed


    If systemcheck sees a failure it has the ability to restart the service. If a high load is detected it will automatically email a administrator. System check also monitors memory, if your memory drops below 10% usable remianing it has the ability to turn off services to try to free up more memory, it is smart enough to turn on and off services in order to prevent a complete crash.

    Note:
    Server load, memory, and diskspace information are gather from other system information tools.

    - Updated: May 16, 2001
    2. Mail Server operation. - Top

    All private servers use sendmail to send email. There is a program called poprelay that does the authentication of ips so you can send email without making a entry in the sendmail relay-host file. poprelay runs as a daemon and gets its information from the maillog. Basically when someone trys to send or receive email its logged by the server in the maillog file, poprelay parses ips for authentication from this file as they are written there. It stores the ips for 15 minutes before resetting in its own authentication file. Poprelay can authenticate most log entries properly, if it cannot authenticate a ip you will need to add it to the sendmail relay domain file to unlock it.

    The maillog and all other log files are generated by a daemon called syslog. Its important that you dont delete log files since it can result in a important service failing. We use the log files to determine what could be going wrong when you cant send mail or receive mail. The first thing you can do before emailing us is make sure both syslog and poprelay are running properly on your server. The easiest way to do this is with the script client_tools, you can goto the Restart menu and choose #8 in the menu to restart all mail services.

    - Updated: June 23, 2001

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