Oracle® Database Backup and Recovery Advanced User's Guide 10g Release 2 (10.2) Part Number B14191-02 |
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Oracle recommends that you allow RMAN to manage the creation and destruction of the auxiliary instance used during RMAN TSPITR. However, creating and using your own auxiliary instance is also supported. One reason you might want to do this is to exercise control of channels used in TSPITR. RMAN's automatic auxiliary instance uses the configured channels of the target database as the basis for the channels to configure on the auxiliary instance and use during restore. If you need different channel settings, and you do not want to use CONFIGURE
to change the settings on the target database, you can operate your own auxiliary instance.
Creating an Oracle instance suitable for use as an auxiliary instance requires that you carry out all of the following steps:
Step 1: Create an Oracle Password File for the Auxiliary Instance
Step 2: Create an Initialization Parameter File for the Auxiliary Instance
Step 3: Check Oracle Net Connectivity to the Auxiliary Instance
For instructions on how to create and maintain Oracle password files, refer to the Oracle Database Administrator's Guide.
Create a client-side initialization parameter file for the auxiliary instance on the machine where you will be running SQL*Plus to control the auxiliary instance. For this example, assume your parameter file is placed at /tmp/initAux.ora
. Set the parameters described in the following table.
Note:
Paths used in parameters such asDB_FILE_NAME_CONVERT
, LOG_FILE_NAME_CONVERT
and CONTROL_FILES
all refer to server-side paths, not client-side.Table 8-2 Initialization Parameters in the Auxiliary Instance
Parameter | Mandatory? | Value |
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YES |
The same name as the target database. |
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YES |
A value different from any database in the same Oracle home. For simplicity, specify |
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YES |
Set to |
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YES |
The same value as the parameter in the target database. |
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YES |
If this initialization parameter is set in the target database, then it must be set to the same value in the auxiliary instance. |
YES |
Patterns to generate filenames for the online redo logs of the auxiliary database based on the online redo log names of the target database. Query This parameter is the only way to name the online redo logs for the auxiliary instance. Without it, TSPITR will fail when trying to open the auxiliary instance because the online logs cannot be created. Note: Some platforms do not support ending patterns in a forward or backward slash ( Note: Some platforms do not support ending patterns in a forward or backward slash ( See Also: "Specifying Auxiliary Instance Online Log Location in TSPITR" for restrictions on possible values for BUG 4673106 - |
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NO |
Patterns to convert filenames for the datafiles of the auxiliary database. You can use this parameter to generate filenames for those files that you did not name with Note: Some platforms do not support ending patterns in a forward or backward slash ( See Also: "Using DB_FILE_NAME_CONVERT to Name Auxiliary Set Datafiles" BUG 4673106 -- no change here, since the "See Also" goes to a section which documents the restriction |
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NO |
Filenames that do not conflict with the control file names of the target instance (or any other existing file). |
Set other parameters as needed, including the parameters that allow you to connect as SYSDBA
through Oracle Net.
The following example shows possible initialization parameter settings for an auxiliary instance for TSPITR:
DB_NAME=trgt DB_UNIQUE_NAME=_trgt CONTROL_FILES=/tmp/control01.ctl DB_FILE_NAME_CONVERT=('/oracle/oradata/trgt/','/tmp/') LOG_FILE_NAME_CONVERT=('/oracle/oradata/trgt/redo','/tmp/redo') REMOTE_LOGIN_PASSWORDFILE=exclusive COMPATIBLE =10.1.0 DB_BLOCK_SIZE=8192
Note:
After setting these initialization parameters, ensure that you do not overwrite the initialization settings for the production files at the target database.See Also:
Oracle Database Net Services Administrator's Guide for more information about Oracle NetIf you are running your own auxiliary instance, then you may find that the sequence of commands required for TSPITR is quite long, if you allocate a complex channel configuration for restoring from backup, or if you are not using DB_FILE_NAME_CONVERT
to control file naming.
You may wish to store the sequence of commands for TSPITR in a command file, a text file under the host operating system. This command file can be read into RMAN using the @
command (or the CMDFILE
command line argument when starting RMAN) to execute the series of commands in the command file.
See "Using RMAN with Command Files" for more details.
When you run your own auxiliary instance, the default behavior is to use the automatic channel configuration of the target instance. However, if you decide to allocate your own channel configuration, you can do so by including the ALLOCATE AUXILIARY CHANNEL
commands in a RUN block along with the RECOVER TABLESPACE
command for TSPITR. Plan out these commands, if necessary, and add them to the sequence of commands you will run to perform your TSPITR.
See the example in "Executing TSPITR With Your Own Auxiliary Instance: Scenario" for details of how to include channel allocation in your TSPITR script.
You may wish to use SET NEWNAME
commands, either to refer to existing image copies of auxiliary set files to improve TSPITR performance, or to assign new names to the recovery set files for after TSPITR. Plan out these commands, if necessary, and add them to the sequence of commands you will run to perform your TSPITR.
With the preparations complete and your TSPITR commands completely planned, you are now ready to carry out your TSPITR. The following steps are required:
Before beginning RMAN TSPITR, use SQL*Plus to connect to the auxiliary instance and start it in NOMOUNT
mode, specifying a parameter file if necessary. For example:
SQL> CONNECT SYS/oracle@aux AS SYSDBA SQL> STARTUP NOMOUNT PFILE='/tmp/initAux.ora'
Remember that the path for the PFILE will be a client-side path, on the machine from which you run SQL*Plus, not a server-side path.
Because the auxiliary instance does not yet have a control file, you can only start the instance in NOMOUNT
mode. Do not create a control file or try to mount or open the auxiliary instance for TSPITR.
Start RMAN connecting to the target and the manually created auxiliary instance:
% rman target / auxiliary sysuser/syspwd@auxiliary_service_name
Now you are ready to run your TSPITR commands. In the simplest case, just execute the RECOVER TABLESPACE... UNTIL
command at the RMAN prompt:
RMAN> RECOVER TABLESPACE ts1, ts2... UNTIL TIME 'time'
If you want to use ALLOCATE CHANNEL
or SET NEWNAME
then create a RUN block which includes those commands before the RECOVER TABLESPACE command.
RUN {
ALLOCATE CHANNEL c1 DEVICE TYPE DISK;
ALLOCATE CHANNEL c2 DEVICE TYPE SBT;
# and so on...
RECOVER TABLESPACE ts1, ts2 UNTIL TIME 'time';
}
Entering a lengthy series of commands in a RUN block can be error-prone. To avoid making mistakes entering the sequence of commands, create a command file (called, for example, /tmp/tspitr.rman
) to store the whole sequence of commands for your TSPITR. Review it carefully to catch any errors. Then run the command file at the RMAN prompt, using this command:
RMAN> @/tmp/tspitr.rman ;
The results will be the same as in the previous example.
The following example shows the execution of a RECOVER TABLESPACE... UNTIL
operation using the following features of RMAN TSPITR:
Managing your own auxiliary instance
Configuring channels for restore of backups from disk and sbt
Using recoverable image copies for some auxiliary set datafiles using SET NEWNAME
Specifying new names for recovery set datafiles using SET NEWNAME
The process used is as follows:
Prepare the auxiliary instance as described in "Preparing Your Own Auxiliary Instance for RMAN TSPITR". Specify "tspitr
" as the password for the auxiliary instance in the password file, and set up the auxiliary instance parameter file /bigtmp/init_tspitr_prod.ora
with the following settings:
db_name=PROD db_unique_name=tspitr_PROD control_files=/bigtmp/tspitr_cntrl.f' db_file_name_convert=('?/oradata/prod', '/bigtmp') log_file_name_convert=('?/oradata/prod', '/bigtmp') compatible=10.1.0 block_size=8192 remote_login_password=exclusive
Create service name pitprod
for the auxiliary instance, and check for connectivity.
Start the auxiliary instance in NOMOUNT state, as shown:
$ sqlplus SQL> connect sys/tspitr@pit_prod as sysdba SQL> startup nomount pfile=/bigtmp/init_tspitr_prod.ora
Start up RMAN, connecting to the auxiliary instance:
% rman target / auxiliary sys/tspitr@pit_prod
Enter the following commands, in a RUN block, to set up and execute the TSPITR:
run { # Specify NEWNAMES for recovery set datafiles SET NEWNAME FOR DATAFILE '?/oradata/prod/clients01.f' TO '?/oradata/prod/clients01_rec.f'; SET NEWNAME FOR DATAFILE '?/oradata/prod/clients02.f' TO '?/oradata/prod/clients02_rec.f'; SET NEWNAME FOR DATAFILE '?/oradata/prod/clients03.f' TO '?/oradata/prod/clients03_rec.f'; SET NEWNAME FOR DATAFILE '?/oradata/prod/clients04.f' TO '?/oradata/prod/clients04_rec.f'; # Specified newnames for some of the auxiliary set # datafiles that have a valid image copy to avoid restores: SET NEWNAME FOR DATAFILE '?/oradata/prod/system01.f' TO '/backups/prod/system01_monday_noon.f'; SET NEWNAME FOR DATAFILE '?/oradata/prod/system02.f' TO '/backups/prod/system02_monday_noon.f'; SET NEWNAME FOR DATAFILE '?/oradata/prod/undo01.f' TO '/backups/prod/undo01_monday_noon.f'; # Specified the disk and SBT channels to use allocate auxiliary channel c1 device type disk; allocate auxiliary channel c2 device type disk; allocate auxiliary channel t1 device type sbt; allocate auxiliary channel t2 device type sbt; # Recovered the clients tablespace to 24 hours ago: RECOVER TABLESPACE clients UNTIL TIME 'sysdate-1'; }
Consider storing this command sequence in a command file and executing the commnand file, to avoid errors.
If the TSPITR operation is successful, then the results are:
The recovery set datafiles are registered in the target database control file under the names specified with SET NEWNAME, with their contents as of the time specified time for the TSPITR.
The auxiliary files are removed by RMAN, including the control files, online logs and auxiliary set datafiles of the auxiliary instance
The auxiliary instance is shut down
If the TSPITR operation fails, the auxiliary files are left on disk for troubleshooting purposes. If RMAN created the auxiliary instance, it is shut down; otherwise it is left in whatever state it was in when the TSPITR operation failed.