(VERSION INFORMATION: Oracle GI & DB11.2.0.3; Red Hat
5u7)
Purpose is to simulate a VLDB environment where you have to
clone your database using tools like Snapshot , BCV, SnapMirror. This scenario
cloned RAC database using ASM to a single database.
Description of test environment: There are two node RAC. The cloned database
was created on the first node.
1)
Setup your storage device to have enough space
for diskgroup clone.
ASMCMD>
lsdsk --candidate –p
/dev/sfe1
Note:
all the necessary configuration on the raw devices as be performed e.g. ASMLib
or UDEV. This lab use UDEV.
2) ASMCMD> lsdsk -k -G data
/dev/sde1
3) As
oracle OS user shutdown the database. Or you can use ALTER SYSTEM
SUSPEND/RESUME database feature, you can suspend I/O to the database, split the
mirror, and make a backup of the split mirror.
srvctl
stop database -d orcl
4)
Create a clone of diskgroup disks. Here, we are
using dd utility; in production environment you may come across some more sophisticated
tools like BCV. In fact, some mirroring tools do not require Oracle DB to
suspend I/O neither shutdown down before you split your mirror (Note: ASM
instance does caching and striping, so be sure of the capability of the tool).
Oracle DB suspend I/O features reduce downtime compare to DB shutdown.
dd
if=/dev/sde1 of=/dev/sdf1 bs=1024k
5)
Use the KFED ASM utility to read and compare the
disks header.
Change directory as root to grid ORACLE_HOME/bin
[root@red1 bin]# cd /u01/app/11.2.0/grid/bin
[root@red1 bin]# ./kfed read /dev/sde1 >
kfed_sde1.log
[root@red1 bin]# ./kfed read /dev/sdf1 >
kfed_sdf1.log
[root@red1 bin]# diff kfed_sde1.log
kfed_sdf1.log
[root@red1 bin]# head kfed_sde1.log
Note that /dev/sdf1 will not be listed among candidate
disks, as in step 1.
ASMCMD> lsdsk --candidate –p
6)
Rename disk group by renamedg command. I used a two-step
method here. You can simply use one step method ($ renamedg dgname=data
newdgname=clone_data verbose=true)
[grid@red1 ~]$ renamedg phase=one
config=cloneasmdisk.conf verbose=true dgname=data newdgname=clone_data
asm_diskstring='/dev/sdf1'
[grid@red1 ~]$ renamedg phase=two
dgname=data newdgname=clone_data config=cloneasmdisk.conf verbose=true
7)
Using the diff(Linux utility) and kfed utility,
verify the success of renamedg operation
[root@red1 bin]# ./kfed read /dev/sdf1 >
kfed_sdf1.log
[root@red1 bin]# diff kfed_sde1.log
kfed_sdf1.log
OR
Query v$asm_diskgroup
SQL> select name from v$asm_diskgroup;
8)
Mount the clone diskgroup.
SQL>alter diskgroup clone_data mount;
OR
ASMCMD> mount clone_data
ASMCMD> lsdg
1.
Create and edit pfile from the source database
SQL> create
pfile='/u01/app/oracle/product/11.2.0/dbhome_1/dbs/clonedb.ora' from spfile;
File
created.
Using an editor, replace +DATA(sorce_diskgroup)
with +CLONE_DATA(clone_diskgroup).
Edit parameters audit_file_dest, dispatchers
Also, substitute as necessary orcl (i.e. my
source instance name) with clodb (name
given to new instance).
After editing, pfile look like
pga_aggregate_target=134217728
sga_target=398458880
*.audit_file_dest='/u01/app/oracle/admin/clodb/adump'
*.audit_trail='db'
*.cluster_database=true
*.compatible='11.2.0.0.0'
*.control_files='+CLONE_DATA'
#FOR control_files
DO NOT USE THE FULL PATH. Also remove old control file
*.db_block_size=8192
*.db_create_file_dest='+clone_data'
*.db_domain='tobi.com'
*.db_name='clodb'
#changing the
database name
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP)
(SERVICE=clodbXDB)'
*.open_cursors=300
*.pga_aggregate_target=132120576
*.processes=200
*.remote_login_passwordfile='exclusive'
*.sessions=225
*.sga_target=398458880
*.undo_tablespace='UNDOTBS1'
*.db_unique_name='clodb'
*.db_create_online_log_dest_1='+CLONE_DATA'
*.cluster_database='false'
Create directory audit_file_dest
mkdir -p /u01/app/oracle/admin/clodb/adump
2.
Create control file trace from source DB:
SQL> alter database backup controlfile to
trace as '/u01/app/oracle/product/11.2.0/dbhome_1/dbs/controltrace.ora';
Edit according. After editing, see below
listings:
CREATE
CONTROLFILE SET DATABASE "CLODB" RESETLOGS NOARCHIVELOG
MAXLOGFILES 192
MAXLOGMEMBERS 3
MAXDATAFILES 1024
MAXINSTANCES 32
MAXLOGHISTORY 292
LOGFILE
GROUP 1 (
'+CLONE_DATA/orcl/onlinelog/group_1.261.839965849'
) SIZE 50M BLOCKSIZE 512,
GROUP 2 (
'+CLONE_DATA/orcl/onlinelog/group_2.262.839965855'
) SIZE 50M BLOCKSIZE 512,
GROUP 3 (
'+CLONE_DATA/orcl/onlinelog/group_3.265.839966205'
) SIZE 50M BLOCKSIZE 512,
GROUP 4 (
'+CLONE_DATA/orcl/onlinelog/group_4.266.839966209'
) SIZE 50M BLOCKSIZE 512
-- STANDBY
LOGFILE
DATAFILE
'+CLONE_DATA/orcl/datafile/system.256.839965691',
'+CLONE_DATA/orcl/datafile/sysaux.257.839965693',
'+CLONE_DATA/orcl/datafile/undotbs1.258.839965695',
'+CLONE_DATA/orcl/datafile/users.259.839965695',
'+CLONE_DATA/orcl/datafile/undotbs2.264.839966043'
CHARACTER SET
AL32UTF8;
3.
Startup new instance for clone database.
[oracle@red1 ~]$ ORACLE_SID=clodb
[oracle@red1 ~]$ export ORACLE_SID
[oracle@red1 ~]$ sqlplus / as sysdba
SQL>
startup nomount
pfile='/u01/app/oracle/product/11.2.0/dbhome_1/dbs/clodb3.ora';
ORACLE instance started.
4.
Create Control file and Rename database
SQL>
@/u01/app/oracle/product/11.2.0/dbhome_1/dbs/cloctl.sql
SQL> select name from v$datafile;
SQL> ALTER TABLESPACE TEMP ADD TEMPFILE ‘+CLONE_DATA/orcl/tempfile/temp.263.839965869'
SIZE 35651584 REUSE AUTOEXTEND ON NEXT
655360 MAXSIZE 32767M;
Note that the “ALTER TABLESPACE TEMP ADD
TEMPFILE …” was copied from control trace created earlier.
5.
Do a little test: creating tablesapce testclone.
SQL> create tablespace testclone datafile
size 10m;
Create spfile to ease your dba task J
SQL> create spfile from
pfile='/u01/app/oracle/product/11.2.0/dbhome_1/dbs/clodb3.ora';
Conclusion:
For Very Large Database, backup time can be
reduced significantly by cloning ASM diskgroups.
Ref
& More reading:
1.
Oracle® Automatic Storage Management Administrator's
Guide 11g Release 2 (11.2)
2.
Oracle® Database Backup and Recovery User's
Guide 11g Release 2 (11.2)
