两台服务器构成的Oracle 11gR2 RAC环境中，其中rac1服务器的私有网卡需要更换，所以在rac2服务器上使用dbca创建数据库的时候只创建了本节点的数据库实例(oracledb1)。当rac1服务器私有网卡更换成功，在rac1服务器执行dbca图形化"add Instance"和执行dbca -silent命令添加实例，都收到下面的报错：
[oracle@rac1 ~]$ dbca -silent -addInstance -gdbName oracledb -nodelist rac1 -instanceName oracledb2 -sysDBAUserName sys -sysDBAPassword oracle_Schic1
Look at the log file "/u01/app/oracle/cfgtoollogs/dbca/oracledb.log" for further details.
[oracle@rac1 ~]$ cat /u01/app/oracle/cfgtoollogs/dbca/oracledb.log
"Adding instance" operation on the admin managed database oracledb requires instance configured on local node. There is no instance configured on the local node "rac1".
该操作放在现有的RAC节点rac2上执行应该就可以了。不过下面我们继续讨论手动在rac1上添加oracledb2实例的步骤：
由于rac2运行着oracledb1实例，所以这里先添加rac1的oracledb2实例，之后再做调整。
1.尝试直接在rac1上启动oracledb2实例。
[root@rac1 bin]# su - oracle
[oracle@rac1 ~]$ export ORACLE_SID=oracledb2
[oracle@rac1 ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Fri Nov 9 02:29:36 2012
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup
ORA-29760: instance_number parameter not specified
instance_number的内容参考文章：http://space.itpub.net/23135684/viewspace-748572
2.确保rac1的ASM实例加载了相关磁盘组。
[root@rac2 bin]# ./crsctl stat res -t
--------------------------------------------------------------------------------
NAME TARGET STATE SERVER STATE_DETAILS
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.ARCH.dg
OFFLINE OFFLINE rac1
ONLINE ONLINE rac2
ora.DATA.dg
OFFLINE OFFLINE rac1
ONLINE ONLINE rac2
......
ora.asm
ONLINE ONLINE rac1 Started
ONLINE ONLINE rac2 Started
......
ora.oracledb.db
1 ONLINE ONLINE rac2 Open
......
[root@rac2 bin]# ./srvctl start diskgroup -g data -n rac1
[root@rac2 bin]# ./srvctl start diskgroup -g arch -n rac1
[root@rac2 bin]# ./crsctl stat res -t
--------------------------------------------------------------------------------
NAME TARGET STATE SERVER STATE_DETAILS
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.ARCH.dg
ONLINE ONLINE rac1
ONLINE ONLINE rac2
ora.DATA.dg
ONLINE ONLINE rac1
ONLINE ONLINE rac2
......
3.调整RAC参数文件。
[root@rac2 bin]# su - oracle
[oracle@rac2 ~]$ export ORACLE_SID=oracledb1
[oracle@rac2 ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Fri Nov 9 02:34:18 2012
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
SQL> create pfile='/tmp/opfile.txt' from spfile='+DATA/oracledb/spfileoracledb.ora';
File created.
SQL> !vi /tmp/opfile.txt
oracledb1.__db_cache_size=60263759872
oracledb1.__java_pool_size=134217728
oracledb1.__large_pool_size=134217728
oracledb1.__pga_aggregate_target=39728447488
oracledb1.__sga_target=68719476736
oracledb1.__shared_io_pool_size=0
oracledb1.__shared_pool_size=7784628224
oracledb1.__streams_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/oracledb/adump'
*.audit_trail='db'
*.cluster_database=true
*.compatible='11.2.0.0.0'
*.control_files='+DATA/oracledb/controlfile/current.260.798857565'
*.db_block_size=8192
*.db_create_file_dest='+DATA'
*.db_domain=''
*.db_name='oracledb'
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=oracledbXDB)'
oracledb1.instance_number=1
oracledb2.instance_number=2
*.log_archive_dest_1='LOCATION=+arch'
*.log_archive_format='%t_%s_%r.dbf'
*.open_cursors=300
*.pga_aggregate_target=39625687040
*.processes=5000
*.remote_listener='wstrac.scan.com:1521'
*.remote_login_passwordfile='exclusive'
*.sessions=5505
*.sga_target=68719476736
oracledb1.thread=1
oracledb2.thread=2
oracledb1.undo_tablespace='UNDOTBS1'
oracledb2.undo_tablespace='UNDOTBS2'
~
"/tmp/opfile.txt" 34L, 1103C written
上面加红的部分是新增加的内容。
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> create spfile='+DATA/oracledb/spfileoracledb.ora' from pfile='/tmp/opfile.txt';
File created.
SQL> startup
ORACLE instance started.
Total System Global Area 6.8413E+10 bytes
Fixed Size 2245480 bytes
Variable Size 8053066904 bytes
Database Buffers 6.0264E+10 bytes
Redo Buffers 93609984 bytes
Database mounted.
Database opened.
增加的参数的含义也参考文章：http://space.itpub.net/23135684/viewspace-748572
4.确保创建了UNDOTBS2表空间。
SQL> select file_id,file_name from dba_data_files;
FILE_ID
----------
FILE_NAME
--------------------------------------------------------------------------------
4
+DATA/oracledb/datafile/users.259.798857305
3
+DATA/oracledb/datafile/undotbs1.258.798857305
2
+DATA/oracledb/datafile/sysaux.257.798857305
FILE_ID
----------
FILE_NAME
--------------------------------------------------------------------------------
1
+DATA/oracledb/datafile/system.256.798857305
5
+DATA/oracledb/datafile/undotbs2.266.798863859
5.再次尝试启动rac1上的oracledb2实例。
SQL> startup
ORACLE instance started.
Total System Global Area 6.8413E+10 bytes
Fixed Size 2245480 bytes
Variable Size 6979325080 bytes
Database Buffers 6.1338E+10 bytes
Redo Buffers 93609984 bytes
ORA-01618: redo thread 2 is not enabled - cannot mount
需要启用 redo thread 2。
6.启用redo thread 2。
以下的操作一定在现存的RAC节点实例上执行（在添加的节点上无法执行），也就是说在rac2节点的oracledb1实例上执行以下命令：
SQL> ALTER DATABASE
2 ADD LOGFILE THREAD 2 GROUP 4
3 ('+DATA') SIZE 256M;
Database altered.
SQL> ALTER DATABASE
2 ADD LOGFILE THREAD 2 GROUP 5
3 ('+DATA') SIZE 256M;
Database altered.
SQL> ALTER DATABASE
2 ADD LOGFILE THREAD 2 GROUP 6
3 ('+DATA') SIZE 256M;
Database altered.
SQL> alter database enable thread 2;
Database altered.
要启动thread 2，必须先为thread 2创建好日志组。
参考文章：http://space.itpub.net/7199859/viewspace-663572
7.加载rac1 oracledb2实例并打开数据库。
SQL> alter database mount;
Database altered.
SQL> alter database open;
Database altered.
经过以上的步骤，成功为rac1节点添加了oracledb2实例。
8.将实例信息添加到OCR中。
[root@rac1 bin]# su - oracle
[oracle@rac1 ~]$ srvctl add instance -d oracledb -i oracledb2 -n rac1
[oracle@rac1 ~]$ srvctl status database -d oracledb
Instance oracledb2 is not running on node rac1
Instance oracledb1 is running on node rac2
[oracle@rac1 ~]$ srvctl start instance -d oracledb -i oracledb2
[oracle@rac1 ~]$ srvctl status database -d oracledb
Instance oracledb2 is running on node rac1
Instance oracledb1 is running on node rac2
9.调整OCR中实例运行节点。
经过上面的添加后，rac1运行着oracledb2实例，rac2运行着oracledb1实例，执行下面的步骤，使得rac1运行oracledb1实例，rac2运行oracledb2实例。
[oracle@rac1 ~]$ srvctl stop database -d oracledb
[oracle@rac1 ~]$ srvctl remove instance -d oracledb -i oracledb1
Remove instance from the database oracledb? (y/[n]) y
[oracle@rac1 ~]$ srvctl remove instance -d oracledb -i oracledb2
Remove instance from the database oracledb? (y/[n]) y
[oracle@rac1 ~]$ srvctl add instance -d oracledb -i oracledb1 -n rac1
[oracle@rac1 ~]$ srvctl add instance -d oracledb -i oracledb2 -n rac2
[oracle@rac1 ~]$ srvctl start database -d oracledb
[oracle@rac1 ~]$ srvctl status database -d oracledb
Instance oracledb1 is running on node rac1
Instance oracledb2 is running on node rac2
[oracle@rac1 ~]$ srvctl enable database -d oracledb
PRCC-1010 : oracledb was already enabled
PRCR-1002 : Resource ora.oracledb.db is already enabled
[oracle@rac1 ~]$ srvctl enable instance -d oracledb -i oracledb1
[oracle@rac1 ~]$ srvctl enable instance -d oracledb -i oracledb2
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