Oracle Concepts - RMAN Catalog Installation Oracle Tips by Burleson Consulting

Installing the RMAN Catalog

The catalog should be owned by a user with the resource role grant. I suggest a user in a small database dedicated to system administration functions such as the RMAN catalog and Enterprise Manager catalog. Create a tablespace for use by the RMAN user and assign that as the user’s default tablespace with unlimited quota. For example, if we wanted our user to be named rman_dba, the steps would be as follows:

sqlplus system/manager
SQL>CREATE TABLESPACE rman_data DATAFILE 'file_spec' DEFAULT STORAGE (clause);
SQL>CREATE USER rman_dba IDENTIFIED BY rman_dba
 2: DEFAULT TABLESPACE rman_data
 3: TEMPORARY TABLESPACE  temp
 4: QUOTA UNLIMITED ON rman_data;
SQL>GRANT RESOURCE,CONNECT TO rman_dba;
SQL>CONNECT rman_dba/rman_dba
SQL> @$ORACLE_HOME/rdbms/admin/catrman.sql

Once the catalog is built, the recovery manager can be utilized. The command is either rman, rman80, or RMAN80 depending on your operating system. There are literally dozens of commands for use with the RMAN facility. I suggest reviewing the Oracle8i Server Backup and Recovery Guide, Release 8.1.5 (or most current release) (Oracle Corporation, 1999) before using RMAN.

The following are some example scenarios showing how the commands can be made into scripts.

Connection to rman in UNIX on early versions can be tricky. On some UNICES the double quote (“) character has to be escaped, and you need to use the double quotes to log into rman (at least on early versions). Assuming the database to be backed up is ORTEST1 with a TNS alias of ORTEST1, the user is as specified earlier, and the catalog database is ORRMAN, the connection to RMAN for the user SYSTEM password MANAGER would look like this:

$ rman ORTEST1\ system/manager@ORTEST1 rcvcat "rman_dbo/rman_dbo@ORRMAN\"

Intuitive, isn’t it? A sample session from Recovery Manager (RMAN) is shown next.

The target database service name in the “tnsnames.ora” file is “ORTEST1.” The recovery catalog database service name in the “tnsnames.ora” file is “ORRMAN.”

% cd $ORACLE_HOME/rdbms/admin
% sqlplus sys/change_on_install@ORRMAN
SQL> grant connect, resource to RMAN_DBA identified by RMAN_DBA;
Grant succeeded.
SQL> connect rman/rman@ORRMAN
Connected.
SQL> @catrman.sql
SQL> exit
%
% rman 'target sys/change_on_install@ORTEST1 rcvcat rman/rman@ORRMAN'
Recovery Manager: Release 8.0.2.0.0 - Beta
RMAN-06005: connected to target database: ORTEST1
RMAN-06008: connected to recovery catalog database
RMAN> register database;                          
RMAN-08006: database registered in recovery catalog
RMAN-08002: starting full resync of recovery catalog
RMAN-08004: full resync complete
RMAN> run    
2> {        
3> allocate channel c1 type disk;
 
4> backup full format '/oracle16/ORTEST1/amin/backup/backup%s%p' (database);
5> }
 
RMAN-08030: allocated channel: c1
 
RMAN-08500: channel c1: sid=12 devtype=DISK

RMAN-08008: channel c1: started datafile backupset

RMAN-08502: set_count=9 set_stamp=280246639 

RMAN-08011: channel c1: including current controlfile in backupset
RMAN-08010: channel c1: including datafile number 1 in backupset
RMAN-08010: channel c1: including datafile number 2 in backupset
     .
     .
     .
RMAN-08010: channel c1: including datafile number 11 in backupset
RMAN-08010: channel c1: including datafile number 12 in backupset
 
RMAN-08013: channel c1: piece 1 created
 
RMAN-08503: piece handle=/oracle16/ORTEST1/admin/backup/backup91 comment=NONE
RMAN-08003: starting partial resync of recovery catalog
RMAN-08005: partial resync complete
RMAN-10030: RPC call appears to have failed to start on channel default
RMAN-10036: RPC call ok on channel default
RMAN-08031: released channel: c1
RMAN> exit

Incomplete restore scenario

The following shows the scenario for an incomplete recovery. The following scenario assumes that:

• You wish to do an incomplete recovery due to an application error that was made at a specific time.

• There are three tape drives.

• You are using a recovery catalog.

TIP:  It is highly advisable to back up the database immediately after opening the database resetlogs.

The following script restores and recovers the database to the time immediately before the user error occurred. The script does the following:

• Starts the database mount and restricts connections to DBA-only users.

• Restores the database files (to the original locations).

• Recovers the data files by either using a combination of incremental backups and redo or just redo. Recovery Manager will complete the recovery when it reaches the transaction from the time specified.

• Opens the database resetlogs.

Oracle recommends that you backup your database after the resetlogs (this is not shown in the example).

Ensure that you set your NLS_LANG and NLS_DATE_FORMAT environment variables. You can set these to whatever you wish—the date format of the following example is the standard date format used for recovery, e.g., for UNIX (csh):

> setenv NLS_LANG AMERICAN
> setenv NLS_DATE_FORMAT 'YYYY-MM-DD:hh24:mi:ss'


Next, start up Server Manager:

SVRMGR> connect internal
Connected.
SVRMGR> startup mount restrict
SVRMGR>exit
 
#  rman target internal/knl@prod1 rcvcat rman/rman@rcat cmdfile case2.rcv
run {
#  The 'set until time' command is for all commands executed 
#  between the { and } braces. Means both restore and recover
#  will both be relative to that point in time.
#  Note that Recovery Manager uses the Recovery Catalog to,
#  determine the structure of the database at that time, and
#  restore it.
#
    set until time '1997-06-23:15:45:00';
#
    allocate channel t1 type 'SBT_TAPE';
    allocate channel t2 type 'SBT_TAPE';
    allocate channel t3 type 'SBT_TAPE';
#
    restore
      (database);
#
#  There is no need to manually catalog logs before recovery,
#  as Recovery Manager does catalog resync from the current
#  control file.
#
    recover
      database;
#
    sql 'alter database open resetlogs';
 

The preceding scenarios are just examples of how to use the recovery manager. Please consult your manual before attempting to use the facility for production work. The RMAN readme file contains valuable insights into RMAN use and has several additional scenarios.

More information on OPEN RESETLOGS is available HERE.

This is an excerpt from the eBook "Oracle DBA made Simple".

For more details on Oracle database administration, see the "Easy Oracle Jumpstart" by Robert Freeman and Steve Karam.  It’s only $19.95 when you buy it directly from the publisher here.