|Oracle 9i under Fedora Core 3 - Installation HOWTO|
ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist Linux Error: 2: No such file or directory
This error happens when you reboot and try to login. You will get lots of errors when the database instance is not mounted/started automatically.
Check /etc/oratab and make sure that *:/opt/oracle/OraHome1 and ordb:/opt/oracle/OraHome1 are set to "Y" (YES).
Try to initialize the database: $ORACLE_HOME/bin/dbstart.
No start entry for SID * at /opt/oracle/OraHome1 in /etc/oratab
This might be caused by a bug in the dbstart script which searches for the sid file in the wrong place.
cp $ORACLE_BASE/admin/$ORACLE_SID/pfile/init_*.ora \
As user oracle:
$ sqlplus SQL> create pfile from spfile; SQL> exit
Run the dbstart script: $ORACLE_HOME/bin/dbstart.