Oracle segmentation fault tips

Question:  I'm getting a segmentation fault when starting the Oracle oratclsh process.  What is a segmentation fault, and how do I fix it?  Is there a problem with my segments?

Answer:  A segmentation fault (core dump) has nothing to do with Oracle data segments.  Instead, segmentation fault is sometimes called a data fault, and a segmentation fault is like a S0C4 on a mainframe, an Oracle program addressing RAM outside the memory fence.  In Oracle, a segmentation fault may be from an "invalid" RAM address, or RAM which has been freed, and is addressed later.  In either case, it may be a bug or an SGA/PGA configuration issue.

An Oracle segmentation fault will generate a core dump, in your CDUMP directory (usually $ORACLE_HOME/admin/$ORACLE_SID/cdump).  Because Oracle does not publish the internal DSECT's (Data Sections), mere mortals cannot read the core dump, and the software owner (Oracle) should be contacted.

For full details on the segmentation fault, gather the resulting core dump an open a Service Request (SR) on MOSC.