When managing an Oracle RAC environment, setting the correct ORACLE_SID is critical. Misconfiguration can prevent the instance from starting or connecting properly.
Problem Description
After checking the environment, the ORACLE_SID was set to RACD instead of the correct instance identifier:
[oracle@node2 ~]$ echo $ORACLE_SID
RACD
[oracle@node2 ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.5.0 - Production on Mon Dec 23 11:13:08 2013
Copyright (c) 1982, 2010, Oracle. All Rights Reserved.
SQL> conn /as sysdba
Connected to an idle instance.
SQL> show parameters sga
ORA-01034: ORACLE not available
Although the CRS resources appeared online, SQL*Plus showed the instance as idle:
[oracle@node2 ~]$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....C1.inst application ONLINE ONLINE node1
ora....C2.inst application ONLINE ONLINE node2
ora.RACD.db application ONLINE ONLINE node2
...
Attempting to start the instance produced:
SQL> startup
ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file '/u01/oracle/product/db_1/dbs/initRACD.ora'
Root Cause
The parameter file name uses the instance name (init<em>SID</em>.ora). In the $ORACLE_HOME/dbs directory, only the correct instance file existed (initRACD2.ora), not initRACD.ora.
[oracle@node2 dbs]$ ll
total 52
-rw-rw---- 1 oracle oinstall 1477 Dec 23 09:07 ab_+ASM2.dat
-rw-rw---- 1 oracle oinstall 1544 Dec 23 09:11 hc_+ASM2.dat
-rw-rw---- 1 oracle oinstall 1544 Dec 23 09:11 hc_RACD2.dat
lrwxrwxrwx 1 oracle oinstall 37 Dec 20 17:42 init+ASM2.ora -> /u01/oracle/admin/+ASM/pfile/init.ora
-rw-r--r-- 1 oracle oinstall 12920 May 3 2001 initdw.ora
-rw-r----- 1 oracle oinstall 8385 Sep 11 1998 init.ora
-rw-r----- 1 oracle oinstall 34 Dec 20 18:42 initRACD2.ora
-rw-r----- 1 oracle oinstall 1536 Dec 20 17:42 orapw+ASM2
-rw-r----- 1 oracle oinstall 1536 Dec 20 18:36 orapwRACD2
[oracle@node2 dbs]$ cat initRACD2.ora
SPFILE='+ZEN/RACD/spfileRACD.ora'
The actual instance name on node2 should be RACD2 (first node uses RACD1). The environment variable ORACLE_SID was set to RACD (lacking the node suffix), which caused the database to look for a non‑existent init file.
Solution
Change the ORACLE_SID to the correct instance name for that node:
export ORACLE_SID=RACD2
Then reconnect and start the database:
[oracle@node2 ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.5.0 - Production on Mon Dec 23 11:14:16 2013
Copyright (c) 1982, 2010, Oracle. All Rights Reserved.
SQL> conn /as sysdba
SQL> startup
ORACLE instance started.
After applying the correct ORACLE_SID, the parameter file initRACD2.ora was located, which pointed to the spfile on ASM. The instance started successfully.
Key Takeaway
In Oracle RAC, the instance name on each node typically includes the node number (e.g., prod1, prod2). Always verify that ORACLE_SID matches the local instance name. Misalignment leads to startup failures with errors ORA-01078 and LRM-00109.