Wednesday, June 24, 2009

duplicate target database from active database

It is always educational to get errors, problems during testing or creation of new systems
especially when you are learning new features or investigating how different configurations
behave and
real lfie cases sometimes are not the same as it described in documentation.

That's why I prefer not to think about configuration of test databases on VM religiously
but to create them in minimal configuration and change it later when errors or problems
are being caught.

It helps to get problems and since they are test servers they can be easily broken, recreated
but experience gained and it can be useful for production support of databases.

Recently testing Data Guard switchover for heterogenous databases (Linux: 32-bit <-> 64-bit)
I created several standby databases on virtual machines where primary is on Linux 32-bit
but one of standby databases is on Linux 64-bit.

So I decided to test one of oracle 11g new features
"duplicate target database ... from active database"
to create standby database on Linux 64-bit from primary which is on 32-bit OS

The prerequisite for that RMAN command is to connect to target(primary) and auxiliary
(future standby) through SQL*Net and static configuration have been added to listener.ora file
on standby host:
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac2)(PORT = 1521))
)
)
SID_LIST_LISTENER=
(SID_LIST=
(SID_DESC=
(SID_NAME=tstp)
(GLOBAL_DBNAME=tstp)
(ORACLE_HOME=/u03/app/oracle/product/11.1.0/db_1)
)
)

where tstp - database name for standby database (the same is for primary)

The primary database was created using dbca in silent mode
dbca -silent                      \
-createDatabase \
-templateName General_Purpose.dbc \
-gdbName tstp \
-sid tstp \
-SysPassword sys \
-SystemPassword sys \
-emConfiguration NONE \
-datafileDestination /u01/oradata \
-storageType FS \
-characterSet WE8ISO8859P15 \
-memoryPercentage 40

and was changed to archivelog mode. I created password file for standby instance
and started it in nomount mode as it required and checked connection to both instance
under sysdba:
rman target sys/sys@tstp auxiliary sys/sys@tsts
Recovery Manager: Release 11.1.0.7.0 - Production on Wed Jun 10 01:58:13 2009
Copyright (c) 1982, 2007, Oracle. All rights reserved.

connected to target database: TSTP (DBID=532361881)
connected to auxiliary database: TSTP (not mounted)

But unfortunately duplicate command failed due to errors:
RMAN> duplicate target database for standby from active database nofilenamecheck;

Starting Duplicate Db at 10-JUN-09
using target database control file instead of recovery catalog
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=170 device type=DISK

contents of Memory Script:
{
backup as copy reuse
file '/u01/app/oracle/product/11.1.0/db_1/dbs/orapwtstp' auxiliary format
'/u03/app/oracle/product/11.1.0/db_1/dbs/orapwtstp' ;
}
executing Memory Script

Starting backup at 10-JUN-09
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=135 device type=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 06/10/2009 01:58:36
RMAN-03015: error occurred in stored script Memory Script
RMAN-03009: failure of backup command on ORA_DISK_1 channel at 06/10/2009 01:58:36
ORA-17627: ORA-12577: Message 12577 not found; product=RDBMS; facility=ORA

I could not find description of the error
ORA-12577 but got description for 17627
oerr ora 17627
17627, 00000, "%s"
// *Cause: An error returned by OCI while sending/receiving message from
// remote instance
// *Action: Look at error message and take appropriate action or contact
// Oracle Support Services for further assistance

All my further attempts somehow to get more meaning of the error failed
and I decided to create standby at the same host as primary.

Preparation steps were the same as for 64-bit server but SID of standby was different - tsts
I checked connection to both instances under sysdba and executed duplicate command.

It was completed without problem and standby database from active database had been created:
RMAN> duplicate target database for standby from active database nofilenamecheck;

Starting Duplicate Db at 10-JUN-09
using target database control file instead of recovery catalog
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=153 device type=DISK
contents of Memory Script:
{
backup as copy reuse
file '/u01/app/oracle/product/11.1.0/db_1/dbs/orapwtstp' auxiliary format
'/u01/app/oracle/product/11.1.0/db_1/dbs/orapwtsts' ;
}
executing Memory Script
...
contents of Memory Script:
{
backup as copy current controlfile for standby auxiliary format '/u01/oradata/tsts/control01.ctl';
sql clone 'alter database mount standby database';
}
executing Memory Script
...
Finished backup at 10-JUN-09

sql statement: alter database mount standby database

contents of Memory Script:
{
set newname for clone tempfile 1 to new;
switch clone tempfile all;
set newname for clone datafile 1 to new;
set newname for clone datafile 2 to new;
set newname for clone datafile 3 to new;
set newname for clone datafile 4 to new;
backup as copy reuse
datafile 1 auxiliary format new
datafile 2 auxiliary format new
datafile 3 auxiliary format new
datafile 4 auxiliary format new
;
sql 'alter system archive log current';
}
executing Memory Script
...
Finished backup at 10-JUN-09

sql statement: alter system archive log current

contents of Memory Script:
{
switch clone datafile all;
}
executing Memory Script
...
Finished Duplicate Db at 10-JUN-09

RMAN> exit


So now I have a couple of things to check and test to understand if "duplicate target database
for standby from active database" can be applied to create standby database on Linux 64-bit
from primary on Linux 32-bit:
1. Creation of standby database from active database on different from primary server but
with the same OS (Linux 32-bit)
2. Try to create standby on 64-bit from primary on 32-bit after all latest Data Guard patches applied
3. Trace RMAN sessions that are failing with ORA- errors during duplicate operation


Have a good day!

3 comments:

Fadel said...

hello there!

I'm having the same issue with duplication a primary 32bit for standby 64bit with active option

I'm glad that it's not only me!

have you made work? any workaround?
just out of curiosity. an alternative I used is to drop the active option and duplicate it from a backupset

thanks!

goryunov said...

Hello Fadel,
unfortunately I have not tried after that to make it working. I just used the old fashion option.
I hope it works in 11.2.0 but have not tried it yet

Unknown said...

I would guess that directories on the side you were clonig to did not exist prior to the duplicate- was the cause of your unexplained errors.