Oracle Recovery Manager (RMAN)

RMAN in Oracle
Oracle Recovery Manager (RMAN)
RMAN was introduced in Oracle8, RMAN has since
been enhanced (in Oracle 9i), enhanced (in Oracle
10g) and enhanced (in Oracle 11g).
Recovery Manager(RMAN) is an Oracle provided (free) utility for backing-up, restoring and
recovering Oracle databases. RMAN ships with the Oracle database and doesn't require a
separate installation. The RMAN executable is located in $ORACLE_HOME/bin directory.
RMAN is a Pro*C application that translates commands to a PL/SQL interface through RPC
(Remote Procedure Call). The PL/SQL calls are statically linked into the Oracle kernel, and
does not require the database to be opened (mapped from the ?/rdbms/admin/recover.bsq
file).

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The RMAN environment consists of the utilities and databases that play a role in backing up
our data. At a minimum, the environment for RMAN must include the following:
The target database to be backed up.
The RMAN client (rman executable and recover.bsq), which interprets backup and
recovery commands, directs server sessions to execute those commands, and records our
backup and recovery activity in the target database control file.
Some environments will also use these optional components:
A recovery catalog database, a separate database schema used to record RMAN
activity against one or more target databases (this is optional, but highly recommended).

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A flash recovery area, called as fast recovery area from 11g release2, a disk location
in which the database can store and manage files related to backup and recovery.

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Media management software, required for RMAN to interface with backup devices
such as tape drives.
Large pool (LARGE_POOL_SIZE) is used for RMAN.

Benefits of RMAN


Some of the benefits provided by RMAN include:
Backups are faster and uses less tapes (RMAN will skip empty blocks)

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Less database archiving while database is being backed-up

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RMAN checks the database for block corruptions

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Automated restores from the catalog

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Files are written out in parallel instead of sequential
RMAN can be operated from Oracle Enterprise Manager, or from command line. Here are
the command line arguments:

Argument

Value

Description

target

quoted-string connect-string for target database

catalog

quoted-string connect-string for recovery catalog

nocatalog

none

cmdfile

quoted-string name of input command file

log

quoted-string name of output message log file

trace

quoted-string name of output debugging message log file

append

none

if specified, log is opened in append mode

debug

optional-args

activate debugging

msgno

none

show RMAN-nnnn prefix for all messages

send

quoted-string send a command to the media manager

pipe

string

building block for pipe names

timeout

integer

number of seconds to wait for pipe input

checksyntax none
$
$
$
$
$
$
$
$
$

rman
rman
rman
rman
rman
rman
rman
rman
rman

if specified, then no recovery catalog

check the command file for syntax errors

TARGET SYS/pwd@target
TARGET SYS/pwd@target NOCATALOG
TARGET SYS/pwd@target CATALOG rman/pwd@cat
TARGET=SYS/pwd@target CATALOG=rman/pwd@cat
TARGET SYS/pwd@target LOG $ORACLE_HOME/dbs/log/rman_log.log APPEND
TARGET / CATALOG rman/pwd@cat
TARGET / CATALOG rman/pwd@cat CMDFILE cmdfile.rcv LOG outfile.txt
CATALOG rman/pwd@cat$ rman @/my_dir/my_commands.txt

Using recovery catalog

One (base) recovery catalog can manage multiple target databases. All the target databases
should be register with the catalog.
Start by creating a database schema (usually named rman), in catalog database. Assign an
appropriate tablespace to it and grant it the recovery_catalog_owner role.
$ sqlplus "/as sysdba"
SQL> create user rman identified by rman default tablespace rmants quota unlimited on
rmants;
SQL> grant resource, recovery_catalog_owner to rman;
No need to grant connect role explicitly, because recovery_catalog_owner role has it.
Log in to catalog database with rman and create the catalog.
$ rman catalog rman/rman
RMAN> create catalog;
RMAN> exit;
Now you can continue by registering your databases in the catalog.

$ rman catalog rman/rman@cat target system/manager@tgt
RMAN> register database;

Using virtual private catalog

A virtual private catalog is a set of synonyms and views that enable user access to a subset
of a base recovery catalog. The owner of the base recovery catalog can GRANT or REVOKE
restricted access to the catalog to other database users. Each restricted user has full
read/write access to his own metadata, which is called a virtual private catalog. The RMAN
metadata is stored in the schema of the virtual private catalog owner. The owner of the base
recovery catalog controls what each virtual catalog user can access.
$ sqlplus "/as sysdba"
SQL> create user vpc identified by vpc default tablespace rmants quota unlimited on
rmants;
SQL> grant resource, recovery_catalog_owner to vpc;
Log in to catalog database with rman and grant the catalog to vpc.
$ rman catalog rman/rman
RMAN> GRANT CATALOG FOR DATABASE target_db TO vpc;
RMAN> exit;
Log in to catalog database with vpc and create the virtual private catalog.
$ rman catalog vpc/vpc
RMAN> CREATE VIRTUAL CATALOG;
RMAN> exit;
$ sqlplus vpc/vpc
SQL>exec rman.DBMS_RCVCAT.CREATE_VIRTUAL_CATALOG;

Recovery Manager commands
ADVISE FAILURE

Will display repair options for the specified failures. 11g
R1 command.

ALLOCATE

Establish a channel, which is a connection between RMAN
and a database instance.

ALTER DATABASE Mount or open a database.
BACKUP

Backup database, tablespaces, datafiles, control files,
spfile, archive logs.

BLOCKRECOVER

Will recover the corrupted blocks.

CATALOG

Add information about file copies and user-managed
backups to the catalog repository.

CHANGE

Update the status of a backup in the RMAN repository.

CONFIGURE

To change RMAN settings.

CONNECT

Establish a connection between RMAN and a target,
auxiliary, or recovery catalog database.

CONVERT

Convert datafile formats for transporting tablespaces and
databases across platforms.

CREATE CATALOG Create the base/virtual recovery catalog.
CREATE SCRIPT

Create a stored script and store it in the recovery
catalog.

CROSSCHECK

Check whether backup items still exist or not.

DELETE

Delete backups from disk or tape.

DELETE SCRIPT

Delete a stored script from the recovery catalog.

DROP CATALOG

Remove the base/virtual recovery catalog.

DROP DATABASE Delete the target database from disk and unregisters it.
DUPLICATE

Use backups of the target database to create a duplicate
database that we can use for testing purposes or to
create a standby database.

EXECUTE SCRIPT Run an RMAN stored script.
EXIT or QUIT

Exit/quit the RMAN console.

FLASHBACK
DATABASE

Return the database to its state at a previous time or
SCN.

GRANT

Grant privileges to a recovery catalog user.

HOST

Invoke an operating system command-line subshell from
within RMAN or run a specific operating system
command.

IMPORT CATALOG

Import the metadata from one recovery catalog into
another recovery catalog.

LIST

List backups and copies.

PRINT SCRIPT

Display a stored script.

RECOVER

Apply redo logs or incremental backups to a restored
backup set in order to recover it to a specified time.

REGISTER

Register the target database in the recovery catalog.

RELEASE
CHANNEL

Release a channel that was allocated.

REPAIR FAILURE

Will repair database failures identified by the Data
Recovery Advisor. 11g R1 command.

Replace an existing script stored in the recovery catalog.
REPLACE SCRIPT If the script does not exist, then REPLACE SCRIPT creates
it.
REPORT

Report backup status - database, files, backups.

Inform RMAN that the SQL statement ALTER DATABASE
OPEN RESETLOGS has been executed and that a new
RESET DATABASE
incarnation of the target database has been created, or
reset the target database to a prior incarnation.
RESTORE

Restore files from RMAN backup.

Perform a full resynchronization, which creates a
snapshot control file and then copies any new or changed
RESYNC CATALOG
information from that snapshot control file to the
recovery catalog.
REVOKE

Revoke privileges from a recovery catalog user.

RUN

To run set of RMAN commands, only some RMAN
commands are valid inside RUN block.

SEND

Send a vendor-specific quoted string to one or more
specific channels.

SET

Settings for the current RMAN session.

SHOW

Display the current configuration.

SHUTDOWN

Shutdown the database.

SPOOL

To direct RMAN output to a log file.

SQL

Execute a PL/SQL procedure or SQL statement (not
SELECT).

STARTUP

Startup the database.

SWITCH

Specify that a datafile copy is now the current datafile,
that is, the datafile pointed to by the control file.

TRANSPORT
TABLESPACE

Create transportable tablespace sets from backup for one
or more tablespaces.

UNREGISTER

Unregister a database from the recovery catalog.

UPGRADE
CATALOG

Upgrade the recovery catalog schema from an older
version to the version required by the RMAN executable.

VALIDATE

To validate. 11g R1 command.

All RMAN commands executed through channels. A channel is a connection (session) from
RMAN to target database. These connections or channels are used to perform the desired
operations.

Flash/Fast Recovery Area (FRA)

Flash recovery area is a disk location in which the database can store and manage files
related to backup and recovery.
To set the flash recovery area location and size,
use DB_RECOVERY_FILE_DEST and DB_RECOVERY_FILE_DEST_SIZE.

RMAN new features in Oracle 10g
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Managing recovery related files with flash recovery area.
Optimized incremental backups using block change tracking (Faster incremental
backups) using a file (namedblock change tracking file). CTWR (Change Tracking Writer) is
the background process responsible for tracking the blocks.

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Reducing the time and overhead of full backups with incrementally updated backups.

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Comprehensive backup job tracking and administration with Enterprise Manager.

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Backup set binary compression.

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New compression algorithm BZIP2 brought in.

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Automated Tablespace Point-in-Time Recovery.

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Automatic channel failover on backup & restore.

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Cross-Platform tablespace conversion.

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Ability to preview the backups required to perform a restore operation.
RMAN> restore database preview [summary];
RMAN> restore tablespace tbs1 preview;

RMAN new features in Oracle 11g Release 1
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Multisection backups of same file - RMAN can backup or restore a single file in
parallel by dividing the work among multiple channels. Each channel backs up one file
section, which is a contiguous range of blocks. This speeds up overall backup and restore
performance, and particularly for bigfile tablespaces, in which a datafile can be sized
upwards of several hundred GB to TB's.
Recovery will make use of flashback logs in FRA (Flash Recovery Area).
Fast Backup Compression - in addition to the Oracle Database 10g backup
compression algorithm (BZIP2), RMAN now supports the ZLIB algorithm, which offers 40%
better performance, with a trade-off of no more than 20% lower compression ratio, versus
BZIP2.
RMAN> configure compression algorithm 'ZLIB' ;
Will backup uncommitted undo only, not committed undo.

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Data Recovery Advisor (DRA) - quickly identify the root cause of failures; auto fix
or present recovery options to the DBA.

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Virtual Private Catalog - a recovery catalog administrator can grant visibility of a
subset of registered databases in the catalog to specific RMAN users.
RMAN> grant catalog for database db-name to user-name;

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Catalogs can be merged/moved/imported from one database to another.

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New commands in RMAN

o

RMAN> list failure;

o

RMAN> list failure errnumber detail;

o

RMAN> advise failure;

o

RMAN> repair failure;

o

RMAN> repair failure preview;

o

RMAN> validate database; -- checks for corrupted blocks

o

RMAN> create virtual catalog;

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RMAN new features in Oracle 11g Release2
The following are new clauses and format options for the SET NEWNAME command:A
single SET NEWNAME command can be applied to all files in a database or tablespace.
SET NEWNAME FOR DATABASE TO format;
SET NEWNAME FOR TABLESPACE tsname TO format;
# New format identifiers are as follows:
# %U - Unique identifier. data_D-%d_I-%I_TS-%N_FNO-%f
# %b - UNIX base name of the original datafile name. For example, if the original datafile
name was $ORACLE_HOME/data/tbs_01.f, then %b is tbs_01.f.

RMAN related views
Control File V$ View

Recovery Catalog View

View Describes

V$ARCHIVED_LOG

RC_ARCHIVED_LOG

Archived and
unarchived redo
logs

V$BACKUP_DATAFILE

RC_BACKUP_CONTROLFILE

Control files in
backup sets

V$BACKUP_CORRUPTION

RC_BACKUP_CORRUPTION

Corrupt block
ranges in datafile
backups

V$BACKUP_DATAFILE

RC_BACKUP_DATAFILE

Datafiles in
backup sets

V$BACKUP_FILES

RC_BACKUP_FILES

RMAN backups
and copies in the
repository

V$BACKUP_PIECE

RC_BACKUP_PIECE

Backup pieces

V$BACKUP_REDOLOG

RC_BACKUP_REDOLOG

Archived logs in
backups

V$BACKUP_SET

RC_BACKUP_SET

Backup sets

V$BACKUP_SPFILE

RC_BACKUP_SPFILE

Server parameter
files in backup
sets

V$DATAFILE_COPY

RC_CONTROLFILE_COPY

Control file copies
on disk

V$COPY_CORRUPTION

RC_COPY_CORRUPTION

Information about
datafile copy

corruptions

V$DATABASE

V$DATABASE_
BLOCK_CORRUPTION

RC_DATABASE

Databases
registered in the
recovery catalog
(RC_DATABASE)
or information
about the
currently
mounted
database
(V$DATABASE)

RC_DATABASE_
BLOCK_CORRUPTION

Database blocks
marked as
corrupt in the
most recent
RMAN backup or
copy

All database
V$DATABASE_INCARNATIO RC_DATABASE_INCARNATIO incarnations
N
N
registered in the
catalog
V$DATAFILE

RC_DATAFILE

All datafiles
registered in the
recovery catalog

V$DATAFILE_COPY

RC_DATAFILE_COPY

Datafile image
copies

V$LOG_HISTORY

RC_LOG_HISTORY

Historical
information about
online redo logs

V$OFFLINE_RANGE

RC_OFFLINE_RANGE

Offline ranges for
datafiles

V$PROXY_ARCHIVEDLOG

RC_PROXY_ARCHIVEDLOG

Archived log
backups created
by proxy copy

V$PROXY_CONTROLFILE

RC_PROXY_CONTROLFILE

Control file
backups created
by proxy copy

V$PROXY_DATAFILE

RC_PROXY_DATAFILE

Datafile backups
created by proxy
copy

V$LOG and V$LOGFILE

V$THREAD

V$RESTORE_POINT

-

RC_REDO_LOG

Online redo logs
for all
incarnations of
the database
since the last
catalog
resynchronization

RC_REDO_THREAD

All redo threads
for all
incarnations of
the database
since the last
catalog
resynchronization

RC_RESTORE_POINT

All restore points
for all
incarnations of
the database
since the last
catalog
resynchronization

RC_RESYNC

Recovery catalog
resynchronization
s

RMAN persistent
V$RMAN_CONFIGURATION RC_RMAN_CONFIGURATION configuration
settings

V$RMAN_OUTPUT

V$RMAN_STATUS
V$TABLESPACE

RC_RMAN_OUTPUT

Output from
RMAN commands
for use in
Enterprise
Manager

RC_RMAN_STATUS

Historical status
information about
RMAN operations

RC_TABLESPACE

All tablespaces
registered in the
recovery catalog,
all dropped
tablespaces, and
tablespaces that

belong to old
incarnations
RC_TEMPFILE

V$TEMPFILE

All tempfiles
registered in the
recovery catalog

RMAN related Packages
DBMS_RCVCAT
DBMS_RCVMAN
DBMS_BACKUP_RESTORE

Source: Internet
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