RAC To Single Instance Physical Standby

RAC to Single Instance Physical Standby
Oracle 11g new feature of active database duplication could also be used for creating standby databases in data guard configurations.
This blog uses the same RAC configuration used for active database duplication to create a single instance physical standby
database.
RAC instances are
olsnodes -n
rac4 1
rac5 2
Data files and logfiles are in two ASM diskgroups called +DATA and +FLASH.
Physical standby database will have it's files in the local file system and will be referred to as stdby through out the blog.
1. Instance Oracle Enterprise Edition software on the host where physical standby will reside. In addition to this also create the
necessary directory structures such as adump ($ORACLE_BASE/admin/sid name/adump) and directories for controlfiles, datafiles
and onlinelogs, though the configuration uses OMF once the setup is completed, these directories are required in the beginning to
complete the setup. (not required if instead of OMF, some other directory path is referenced). For this configuration following
directories were created
cd /data/oradata
mkdir STDBY
cd STDBY
mkdir controlfile datafile onlinelog
cd cd /data/flash_recovery
mkdir STDBY
cd STDBY
mkdir onlinelog
2. Create TNS entries on both RAC node's tnsnames.ora file
STDBYTNS =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = standby-host)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SID = stdby)
)
)
3. Create TNS entry on the standby's tnsnames.ora file
PRIMARYTNS =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac1-host)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = rac11g2)
)
)
In this case only one instance will be used to fetch archive log gaps and to send redo when the switch over happens. In a RAC
standby multiple instances can receive but there can only be one applier.
4. Add a static listener entry to listener.ora
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = stdby)
(SID_NAME = stdby)
(ORACLE_HOME = /opt/app/oracle/product/11.2.0/ent)
)
)
5. Enable force logging on the primary
SQL> alter database force logging;
6. Create standby log files for each thread on primary. These should be same size as the online redo log files
SQL> alter database add standby logfile thread 1 size 52428800;
or
SQL> alter database add standby logfile thread 1;

SQL> alter database add standby logfile thread 2;
There should be at least one more redo log group per thread than the online redo logs.
6. Add Data Guard related initialization parameters to primary. These include, information about the instances involved in the data
guard configuration, redo transport parameters such SYNC,ASYNC, AFFIRM, NOAFFIRM, fetch archive log client and server values
and datafile/logfile name conversions.
alter system set log_archive_config='dg_config=(rac11g2,stdby)' scope=both ;

alter system set log_archive_dest_1='location=use_db_recovery_file_dest
valid_for=(all_logfiles,all_roles) db_unique_name=rac11g2' scope=both;
alter system set log_archive_dest_2='service=STDBYTNS LGWR ASYNC NOAFFIRM
max_failure=10 max_connections=5 reopen=180
valid_for=(online_logfiles,primary_role) db_unique_name=stdby' scope=both;
alter system set log_archive_dest_state_1='enable' scope=both;
alter system set log_archive_dest_state_2='enable' scope=both;
alter system set fal_server='STDBYTNS' scope=both;
alter system set fal_client='PRIMARYTNS' scope=both;
alter system set log_archive_max_processes=10 scope=both;
alter system set db_file_name_convert='/data/oradata/STDBY','+DATA/rac11g2'
scope=spfile;
alter system set
log_file_name_convert='/data/flash_recovery/STDBY','+FLASH/rac11g2'
scope=spfile;
alter system set standby_file_management='AUTO' scope=both;
7. Copy the password file to standby host's ORACLE_HOME/dbs and rename the file. Assuming password file is copied to the
standby host
mv orapwrac11g22 orapwstdby
8. create a pfile with db_name as the only entry.
*.db_name='stdby'
9. Start the standby instance using the above mentioned pfile in nomount mode
startup nomount pfile=initstdby.ora
10. On the primary using rman connect to primary db as target and standby as the auxiliary and run the active duplication command
to create the standby. Some of the RAC only parameters has been reset while others have been set to reflect the standby database
after switch over.
rman target / auxiliary sys/rac11g2db@stdbytns
duplicate target database for standby from active database

spfile
parameter_value_convert 'rac11g2','stdby','RAC11G2','stdby'
set db_unique_name='stdby'
set
db_file_name_convert='+DATA/rac11g2','/data/oradata/STDBY','+DATA/rac11g2/temp
file','/data/oradata/STDBY'
set
log_file_name_convert='+FLASH/rac11g2','/data/flash_recovery/STDBY','+DATA/rac
11g2','/data/flash_recovery/STDBY'
set control_files='/data/oradata/stdby/controlfile/control01.ctl'
set log_archive_max_processes='5'
set fal_client='STDBYTNS'
set fal_server='PRIMARYTNS'
SET cluster_database='false'
reset REMOTE_LISTENER
reset local_listener
set db_create_file_dest = '/data/oradata'
set db_recovery_file_dest = '/data/flash_recovery'
set standby_file_management='AUTO'
set log_archive_config='dg_config=(rac11g2,stdby)'
set log_archive_dest_2='service=PRIMARYTNS LGWR ASYNC NOAFFIRM max_failure=10
max_connections=5 reopen=180 valid_for=(online_logfiles,primary_role)
db_unique_name=rac11g2'
set log_archive_dest_1='location=use_db_recovery_file_dest
valid_for=(all_logfiles,all_roles) db_unique_name=stdby';
This will start the duplication and creation of the physical standby
Starting Duplicate Db at 30-NOV-10

using target database control file instead of recovery catalog
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=10 device type=DISK
contents of Memory Script:

{
backup as copy reuse
targetfile '/opt/app/oracle/product/11.2.0/db_1/dbs/orapwrac11g22' auxiliary
format
'/opt/app/oracle/product/11.2.0/ent/dbs/orapwstdby' ;
}
executing Memory Script
...
...
...
Finished Duplicate Db at 30-NOV-10
If any parameter setting has some configuration mismatches and still referrers to ASM for files then the duplication process will
terminate with
ERROR: slave communication error with ASM; terminating process 21416

Errors in file
/opt/app/oracle/diag/rdbms/stdby/stdby/trace/stdby_lgwr_21416.trc:
Mon Nov 29 17:40:49 2010
PMON (ospid: 21396): terminating the instance due to error 470
Instance terminated by PMON, pid = 21396
11. Once successfully completed start redo apply on the standby with
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE

DISCONNECT
12. Force a log switch on the primary
alter system switch logfile;
or
alter database archive log current;
13. Check if the logs are applied on the standby with
select thread#,sequence#,applied from v$archived_log;
THREAD# SEQUENCE# APPLIED

---------- ---------- ---------
1 108 YES
1 109 YES
1 110 YES
1 111 YES
2 98 YES
2 99 YES
2 100 YES
1 112 IN-MEMORY

RAC To Single Instance Physical Standby

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RAC to Single Instance Physical Standby

RAC instances are

directories were created

2. Create TNS entries on both RAC node's tnsnames.ora file

3. Create TNS entry on the standby's tnsnames.ora file

4. Add a static listener entry to listener.ora

5. Enable force logging on the primary

SQL> alter database force logging;

SQL> alter database add standby logfile thread 1 size 52428800;

SQL> alter database add standby logfile thread 1;

and datafile/logfile name conversions.

alter system set log_archive_config='dg_config=(rac11g2,stdby)' scope=both ;

8. create a pfile with db_name as the only entry.

startup nomount pfile=initstdby.ora

after switch over.

rman target / auxiliary sys/rac11g2db@stdbytns

duplicate target database for standby from active database

Starting Duplicate Db at 30-NOV-10

contents of Memory Script:

ERROR: slave communication error with ASM; terminating process 21416

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE

12. Force a log switch on the primary

alter system switch logfile;

alter database archive log current;

13. Check if the logs are applied on the standby with

select thread#,sequence#,applied from v$archived_log;

THREAD# SEQUENCE# APPLIED

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