ORA-27300 ORA-27301 ORA-27302

ORA-27300 ORA-27301 ORA-27302

Error Detail (InAlert.log file):

Sun Nov 16 06:00:02 2014

WARNING: process USER (ospid: 26006) was unable to attach SMR.

Errors in file /u01/app/oracle/diag/rdbms/rpst01/rpst01/trace/rpst01_j002_26006.trc:

ORA-27300: OS system dependent <E5> tg <E4> rd: open utf <F6> Rdes not with the status: 2
ORA-27301: OS error: No such file or directory
ORA-27302: error occurred in: sskgmsmr_7

Error Description

SMR stands for shared memory region and we have this instance monitoring segment which is used to store data for health monitoring. Every process which starts up attaches to this and the data in this segment is visible to whoever has this SMR as part of its address space. This gets called during SGA initialization for creation of the shared memory segment and attaching to it.

- The SMR name is constructed from the Oracle Home Name and the SID

- The file which this data is stored in is $ORACLE_HOME/dbs/hc_<SID>.dat

This file is also used by the EM agent to determine the database status.

Reason:

1.       DB might have been upgraded recently during which some files has been manually deleted.

2.       Few Files in $ORACLE_HOME/dbs location could have been deleted while database was running. 

Solution:

In my case hc_<SID>.dat file was not present due to which error was being logged into log file. Luckily, this file is created during the database startup and hence restarting the database resolved this issue. If the file has been moved recently to another location, relocating the file back to dbs location might also resolve.