Tag Archives: rac

How to Solve Rac ORA-01102 error: cannot mount database in EXCLUSIVE mode

The following error occurs when starting an Oracle 11g RAC database. Only one of the nodes (rac01) can be started, and the other node cannot be started (rac02). This may be caused by a previous change to the cluster_database parameter. In Oracle RAC architecture this parameter must be set to TRUE.

When executing startup, the error message: ORA-01102: cannot mount database in EXCLUSIVE mode

Solution:

rac01 node:

SQL> show parameter cluster_database;

NAME TYPE VALUE

———————————— ———– ——————————

cluster_database boolean FALSE

cluster_database_instances integer 1

SQL> alter system set cluster_database=true scope=spfile;

System altered.

SQL> shutdown immediate

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

Total System Global Area 1068937216 bytes

Fixed Size 2260088 bytes

Variable Size 734004104 bytes

Database Buffers 327155712 bytes

Redo Buffers 5517312 bytes

Database mounted.

Database opened.

SQL> select open_mode from v$database;

OPEN_MODE

——————–

READ WRITE

SQL> show parameter cluster_database;

NAME TYPE VALUE

———————————— ———– ——————————

cluster_database boolean TRUE

cluster_database_instances integer 2

SQL>

rac02 node:

[oracle@fanxin02 ~]$ sqlplus/as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Tue May 21 23:08:16 2019

Copyright (c) 1982, 2013, Oracle. All rights reserved.

Connected to an idle instance.

SQL> startup ORACLE instance started.

Total System Global Area 1068937216 bytes

Fixed Size 2260088 bytes

Variable Size 734004104 bytes

Database Buffers 327155712 bytes

Redo Buffers 5517312 bytes

Database mounted.

Database opened.

SQL> show parameter cluster_database;

NAME TYPE VALUE

———————————— ———– ——————————

cluster_database boolean TRUE

cluster_database_instances integer 2

SQL>

SQL> archive log list;

Database log mode Archive Mode

Automatic archival Enabled

Archive destination /u01/app/oracle/product/11.2.0.4/db_1/dbs/arch

Oldest online log sequence 12

Next log sequence to archive 13

Current log sequence 13

SQL>