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Oracle Troubleshooting

Database Instance Failure

Symptom:

The database instance is no longer running.

Possible Causes:

  • The DBA has taken the instance down.
  • The server has been shut down.
  • The server has rebooted and the instance has not been set to auto-start.
    • Check the NT System Event Log to see if the server has been rebooted.
  • Some other hardware related problem.

    • Check the Windows System Event Log

  • Other sources of information to check for additional clues as to the probable cause are:
    • {ORACLE_HOME}\RDBMS80\TRACE\<sid>ALRT.LOG
    • {ORACLE_HOME}\RDBMS80\TRACE\<sid>LMON.TRC

      Note: From Oracle 8.1.5 onwards, these files are instead located in the directory {ORACLE_HOME}\Admin\{DB-Name>\bdump

    • Check that the normal Oracle services are running.
  • If running OPS then also check the ‘errlog’ and ‘pgms.log’ files, both of which are located in the ‘WinNT\System32’ directory.

Remedy:

The remedy will depend on the reason for the instance failure.

This page represents one page of many pages of notes I made whilst working with Oracle 7 through to 10i. I now no longer work with Oracle databases, but hope that these notes will continue to be of benefit to others.

About the author: is a dedicated software developer and webmaster. For his day job he develops websites and desktop applications as well as providing IT services. He moonlights as a technical author and consultant.