How to resolve ORA-01102: cannot mount database in exclusive mode?

POSSIBLE SOLUTION: Verify that the database was shutdown cleanly by doing the following:

1. Verify that following files do not exist
"$ORACLE_HOME/dbs/sgadef<sid>.dbf"
"$ORACLE_HOME/dbs/lk<sid>"
If these file exists, remove them.

rm $ORACLE_HOME/dbs/sgadef<sid>.dbf
rm $ORACLE_HOME/dbs/lk<sid>


2. Verify that there are no background processes owned by "oracle"

% ps -ef | grep ora_ | grep $ORACLE_SID

If background processes exist, remove them by using the Unix command "kill". For example:

% kill -9 <Process_ID_Number>

3. Startup the instance

If you do not have any other database running on this server then you can also try :-

3. Verify that no shared memory segments and semaphores that are owned by "oracle" still exist


ipcs -b

If there are shared memory segments and semaphores owned by "oracle", remove the shared memory segments

ipcrm -m <Shared_Memory_ID_Number>

and remove the semaphores

ipcrm -s <Semaphore_ID_Number>