ORA-01102: cannot mount database in EXCLUSIVE mode

ORA-01102: cannot mount database in EXCLUSIVE mode


Issue:

After installing 11gR2, i faced issue of ORA-01102 cannot mount database in EXCLUSIVE mode when i tried to start the database.

ORA-01102: cannot mount database in EXCLUSIVE mode

SQL> alter database mount;
alter database mount
*
ERROR at line 1:
ORA-01102: cannot mount database in EXCLUSIVE mode
Here is how I resolved it:

>> Shutdown database

SQL> shutdown immediate;
ORA-01507: database not mounted

>> Find out all the processes belonging to the database still running

ps -ef | grep ora_ | grep $ORACLE_SID

>>  Kill all the processes related to SID only

[oracle@DEV dbs]$ kill -9 324531

>> Check that there are no more processes running

ps -ef | grep ora_ | grep $ORACLE_SID

>> Remove the lk<SID> file from $ORACLE_HOME/dbs location
----------------------------
[oracle@DEV dbs]$ cd $ORACLE_HOME


[oracle@DEV dbs]$ cd dbs/


[oracle@DEV dbs]$ ls
 hc_DEV.dat  init.ora  lkDEV  orapwDEV  spfileDEV.ora


[oracle@DEV dbs]$ rm lkDEV

>>  Start the database
-------------------
SQL> startup
ORACLE instance started.

Total System Global Area 1653518336 bytes
Fixed Size                  2213896 bytes
Variable Size             956303352 bytes
Database Buffers          687865856 bytes
Redo Buffers                7135232 bytes
Database mounted.
Database opened.