Download Migrate a RAC Database to a Single Instance Database on another

Author: Ernie
Migrate a RAC Database to a Single Instance Database on another Server
You can use DBCA, RCONFIG or Enterprise Manager to migrate a Single instance database to a RAC
database, but how do you convert a RAC database to a Single instance database?
This document details the steps I took to migrate a RAC database to a single instance database on to
another Linux server.
Step
1. Install or Verify Linux packages
Command
As the root user Verify that the following packages are
installed:
libXp-1.0.0-8.1.el5.i386.rpm
libXp-1.0.0-8.1.el5.x86_64.rpm
libaio-devel-0.3.106-5.x86_64.rpm
2. Create Oracle O/S Accounts
Create OS Groups:
As root user:
/usr/sbin/groupadd -g 502 dba
/usr/sbin/groupadd -g 501 oinstall
/usr/sbin/groupadd -g 503 oper
/usr/sbin/groupadd -g 504 asmadmin
/usr/sbin/groupadd -g 506 asmdba
Create Oracle OS group and owner and
asm accounts on new node before
attempting this exercise.
Before installing Oracle software set the
correct profile and permissions for the
file systems where the Installation and
database in going to reside.
Create Oracle User:
/usr/sbin/useradd -u 502 -g oinstall -G dba,asmdba oracle
/usr/sbin/useradd -u 502 -g oinstall -G dba oracle
Set Permissions:
chown -R oracle:oinstall /u01
chown -R oracle:oinstall /u02
chown oracle:oinstall /etc/oratab
chmod 775 /etc/oratab
3. Configure ulimits and kernel
parameters.
As root user set Resource Limits & Kernel Parameters:
vi /etc/security/limits.conf
oracle
oracle
oracle
oracle
oracle
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soft
hard
soft
hard
soft
nproc
nproc
nofile
nofile
stack
2047
16384
1024
65536
10240
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vi /etc/sysctl.conf
fs.aio-max-nr = 1048576
fs.file-max = 6815744
kernel.shmall = 2097152
kernel.shmmax = 4294967295
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
net.ipv4.ip_local_port_range = 9000 65500
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576
4. Install Oracle Software
Run the Oracle Installer and Install the software.
Once the Oracle OS Accounts has been
created and Kernel parameters and
resource limits and permissions have been
set then proceed with Oracle Installation.
5. Logon as the Oracle user on the
production system and set the correct
Oracle environment for the database
. oraenv <sid_name>
6. Connect as sysdba
sqlplus as sysdba
7. Execute the following command to
switch logfile and backup the control file
to trace
alter system switch logfile;
alter database backup controlfile to trace;
8. Perform an offline Rman backup if
possible of your production system,
otherwise run a compressed online
backup to disk and include archivelogs.
This backup will be used to restore as a
single Instance to another node.
Set the CONTROLFILE
AUTOBACKUP on so that we have the
controlfile backed up after the database
backup.
Set up Rman scripts for restore on new
node.
connect target /
run{
allocate channel t1 device type disk1;
backup
incremental level 0
cumulative as compressed backupset
format '/backup/rman/dbname/rman_%U'
tag 'RMAN_DB_FULL'
backup
as compressed backupset
format '/backup/rman/dbname/rman_arch_%U'
tag 'RMAN_ARC'
archivelog all;
backup
current controlfile format
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'/backup/rman/dbname/rman_rman_cntrl_%u'
tag 'RMAN_CNTRL';
release channel ch_disk1;
}
9. From the production RAC system create
a pfile from the spfile for the single
instance database and copy pfile across to
new node
Create pfile from spfile;
10. Check the file systems if it differs from
the RAC system then modify the
following parameters according to file
system structure on the new node in your
pfile:
audit_file_dest, background_dump_dest,
control_files, core_dump_dest,
log_archive_dest_1, user_dump_dest
ftp <pfile_name> to new server
11. Remove all RAC specific parameters
Edit and modify pfile accordingly.
in pfile such as cluster_database_instances,
cluster_database
12. Modify pfile undo_tablespace
parameter and use any one of the undo
tablespace names UNDOTBS1 or
UNDOTBS2
Edit and modify pfile accordingly
undo_tablespace = UNDOTBS1
13. Once the rman database backup and
archive backup pieces have been copied
to the new server and also pfile have
modified accordingly then: startup
instance on new server.
. oraenv <sid_name>
sqlplus “/ as sysdba”
startup nomount pfile=’$Oracle_Home’/dbs/initdbname.ora
14. Connect to an Rman session on new
server - set DBID and restore controlfile
from backup piece on new node
rman target / nocatalog
set DBID=12345678;
restore controlfile to '/u01/oradata/dbname/cntrl01.ctl' from
'/backup/rman/dbname/cntrl_auto_c-387244080420130306-11';
15. Once the controlfile has been restored
successfully – mount the database.
alter database mount;
16. If the RMAN backup pieces have been
copied to exactly the same location they
were backed up on production then you
may proceed with the restore, if not
catalog the backup pieces.
catalog start with '/backup/rman/dbname';
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17. While connected to rman identify the
point up to which media recovery should
run on the restored database.
list backup of archivelog all;
18. Restore database and point it to new
location if necessary.
run
{
set newname for datafile 1 to
'/u02/oradata/dbname/system.273.716601193';
set newname for datafile 2 to '/u01/oradata/dbname
/undotbs1.272.716601197';
set newname for datafile 3 to '/u02/oradata/dbname
/sysaux.279.716601197';
set newname for datafile 4 to '/u01/oradata/dbname
/undotbs2.280.716601201';
set newname for datafile 5 to '/u01/oradata/dbname
/file.dbf';
set newname for datafile 6 to '/u01/oradata/dbname
/isastore_data.283.716605103';
set newname for datafile 7 to '/u01/oradata/dbname
/data.263.716605113';
set newname for datafile 8 to '/u02/oradata/dbname
/data.265.716605123';
set newname for datafile 9 to '/u02/oradata/dbname
/data.264.716605135';
set newname for datafile 10 to '/u02/oradata/dbname
/data.271.716605151';
set newname for datafile 11 to '/u02/oradata/dbname
/data.277.737816949';
set newname for datafile 12 to '/u02/oradata/dbname
/data.536.740755877';
set newname for datafile 13 to '/u02/oradata/dbname
/logminer_data.740.742650801';
restore database;
switch datafile all;
recover database noredo;
}
19. Check production system archive
format and modify accordingly:
alter system set log_archive_format = 'log_%t_%s_%r.arc'
scope =spfile;
show parameter DB_RECOVERY_FILE_DEST
alter system set DB_RECOVERY_FILE_DEST =
'/u02/oradata/ dbname/archive';
Set archive location on file system.
20. Once the database has been restored
and you have identified the point up to
which media recovery should run, start the
restore process.
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rman target /
catalog start with '/backup/rman/arch';
run
{
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Catalog the archivelogs and start the
recovery process.
set archivelog destination to '/u02/oradata/dbname/archive';
set until sequence 157320 thread 2;
recover database;
}
21. Once the restore and recovery has
completed then rename the redo logs and
point to file system locations as it is still
pointing to ASM
alter database rename file alter database rename file
'+DG_DATA/dbname/onlinelog/group_20.2862.7616721
79' to '/u02/oradata/dbname/redo20.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_21.2950.7616721
97' to '/u02/oradata/dbname/redo21.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_22.2802.7616722
03' to '/u02/oradata/dbname/redo22.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_23.2937.7616722
11' to '/u02/oradata/dbname/redo23.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_24.2623.7616722
17' to '/u02/oradata/dbname/redo24.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_25.2896.7616722
33' to '/u02/oradata/dbname/redo25.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_26.2174.7616722
39' to '/u02/oradata/dbname/redo26.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_27.2790.7616722
51' to '/u02/oradata/dbname/redo27.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_30.2669.7616722
17' to '/u02/oradata/dbname/redo30.log';
alter database rename file
'+DG_DATA/dbname/onlinelog/group_31.1954.761672225'
to '/u02/oradata/dbname/redo31.log';
select member from v$logfile;
22. Proceed to open database
alter database open resetlogs;
23. Once the database has been opened
successfully, proceed to remove the redo
log groups for redo threads of other
instances.
select THREAD#, STATUS, ENABLED
from v$thread;
select group# from v$log where THREAD#=2;
alter database disable thread 2;
alter database drop logfile group 23;
alter database clear unarchived logfile group 23;
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24. If there are any ora-00312 errors– then
clear all unarchived logfiles and ensure
that the correct archivelog location has
been set
'/u02/oradata/dbname/redo23.log'
ORA-16032: parameter
LOG_ARCHIVE_DEST_1 destination
string cannot be translated
ORA-19801: initialization parameter
DB_RECOVERY_FILE_DEST is not
set
25. Drop the other undo tablespace of the
second node.
sho parameter undo;
select tablespace_name from dba_tablespaces where
contents='UNDO';
drop tablespace UNDOTBS2 including contents and
datafiles;
26.
Drop and re-create temporary tablespace
and alter database to user new temp
tablespace
select tablespace_name from dba_tablespaces where
contents='TEMPORARY';
create temporary tablespace TEMP2 tempfile
'/u01/oradata/dbname//temp01.dbf' size 2000M;
alter tablespace TEMP2 add tempfile
'/u01/oradata/dbname/temp02.dbf' size 2000M;
alter database DEFAULT TEMPORARY TABLESPACE
TEMP2;
drop tablespace TEMP including contents and datafiles;
Applications need to point to new node where single
instance has been setup and configured for testing etc
27. Setup listener and tnsnames files to
point to new database and ensure that the
connections to the database are fine.
Author: Ernie
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