Oracle File Lock Issue | ORA-00202 and ORA-27086

Oracle File Lock Issue | ORA 00202 and ORA 27086

On Oracle Database Startup, if you face the below mentioned error i.e.

ALTER DATABASE   MOUNT

Wed Oct 12 14:29:35 2016

ORA-00202: controlfile: '/database2/database/neoapr11/control01.ctl'

ORA-27086: unable to lock file - already in use

Linux-x86_64 Error: 11: Resource temporarily unavailable

Additional information: 8

then below mentioned is the resolution for you.

Cause:

There can be 2 main reasons for getting ORA-00202 and ORA-27086 errors while working with Oracle Database.

1) Either the problem is OS related. In such kind of scenarios, a system restart would be able to fix your issue dramatically. Sometimes these issues are better to be handled at OS level because after all your efforts you might not be able to release the file lock status.

2) The Shared Memory Segments are already occupied and you need to free them before you can open a fresh instance. This same can be done by system restart but if still the problem persists then you may follow the below mentioned commands to get your issue resolved.

Resolution:

For Unix/Linux System, 

   

   a) ipcs -m

   b) ipcrm -m <segment id number>

      

   c) ipcs -s

      

   d) ipcrm -s <segment id number>

The approach is guided to be done for an ideal Environment where we are having one Oracle Database on a system. If there are multiple Environments running for Oracle Database, then shutdown all of them first and then run the above mentioned commands.

NOTE:

As mentioned in Oracle Support Note 123322.1, we have also the option of using SYSRESV utility to cleanup shared memory segments and semaphores.

ALSO:
Oracle has also referred the same issue as a bug for some specific versions and provided the resolution for the same as mentioned in
Bug 8727960 : LX64: DATAFILES ON NFS, ORA-01157: CANNOT IDENTIFY/LOCK DATA FILE 202 (unpublished Bug)

Kindly go through proper Oracle Support Documentation in order to know more about this Bug in details.