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Oracle® Database Backup and Recovery Reference
11g Release 1 (11.1)

B28273-03
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CONFIGURE

Purpose

Use the CONFIGURE command to create or change a persistent configuration affecting RMAN backup, restore, duplication, and maintenance jobs on a particular database. A configuration is in effect for any RMAN session on this database until the configuration is explicitly cleared or changed. You can use the SHOW command to display the configurations for one or more databases.

See Also:

Oracle Database Backup and Recovery User's Guide to learn how to configure the RMAN environment

Additional Topics

Prerequisites

Execute this command only at the RMAN prompt.

Unless you specify the FOR DB_UNIQUE_NAME clause, an RMAN connection to a target database is required. The target database must be mounted or open.

Usage Notes

The CONFIGURE command always stores a configuration for a target database in the target database control file. If you use RMAN with a recovery catalog, then RMAN also stores persistent configuration settings for each registered database in the catalog.

Default RMAN Configuration Settings

The RMAN CONFIGURE settings have defaults. You can return to the default for any CONFIGURE command by rerunning the command with the CLEAR option, but you cannot clear individual parameters in this way. For example, you can run

CONFIGURE CHANNEL DEVICE TYPE sbt CLEAR

but not

CONFIGURE CHANNEL DEVICE TYPE sbt MAXPIECESIZE 5M CLEAR

RMAN Configuration in a Data Guard Environment

In a Data Guard environment, Oracle recommends that you always use RMAN with a recovery catalog. You can use the CONFIGURE command to create persistent RMAN configurations for any individual primary or standby database in the Data Guard environment, with the exception of settings for backup retention policy, tablespace exclusion, and auxiliary names. Thus, the primary and standby databases can have different channel configurations, control file autobackup locations, and so on.

You can use the FOR DB_UNIQUE_NAME clause to configure a database to which RMAN is not connected as TARGET. You can use CONFIGURE DB_UNIQUE_NAME to make a new physical standby database known to the recovery catalog and implicitly register it.

Syntax

configure::=

Description of configure.gif follows
Description of the illustration configure.gif

(datafileSpec::=, backupConf::=, cfauConf::=, deviceConf::=, forDbUniqueNameOption::=)

delalConf::=

Description of delalconf.gif follows
Description of the illustration delalconf.gif

(deviceSpecifier::=)

backupConf::=

Description of backupconf.gif follows
Description of the illustration backupconf.gif

(deviceSpecifier::=, sizeSpec::=)

cfauConf::=

Description of cfauconf.gif follows
Description of the illustration cfauconf.gif

(deviceSpecifier::=, formatSpec::=)

deviceConf::=

Description of deviceconf.gif follows
Description of the illustration deviceconf.gif

(deviceSpecifier::=, allocOperandList::=)

sizeSpec::=

Description of sizespec.gif follows
Description of the illustration sizespec.gif

forDbUniqueNameOption::=

Description of fordbuniquenameoption.gif follows
Description of the illustration fordbuniquenameoption.gif

Semantics

configure

Syntax Element Description

DB_UNIQUE_NAME
db_unique_name
{CLEAR | CONNECT IDENTIFIER
'connect_string'}
Specifies the net service name for the physical standby database specified by DB_UNIQUE_NAME. The CONNECT IDENTIFIER string must not include the database username and password.

RMAN must also be connected to the primary database as TARGET. RMAN must be connected to a recovery catalog.

When you run the RESYNC CATALOG FROM DB_UNIQUE_NAME command, databases in a Data Guard environment use the net service name to connect with the db_unique_name database. For example, assume that a standby database has the unique name standby1 and the net service name sby1. You connect RMAN as TARGET to the primary database and execute CONFIGURE DB_UNIQUE_NAME 'standby1' CONNECT IDENTIFIER 'sby1'. Every primary and standby database in the environment will use the net service name sby1 when it needs to make an Oracle Net connection to standby1.

Note: When the target database needs to connect to other standby or primary databases, it connects as the SYS user by using the existing Data Guard authentication mechanisms.

Suppose that you recently connected RMAN as TARGET to the primary database and used CONFIGURE ... FOR DB_UNIQUE_NAME standby_new to configure backup settings for standby database standby_new. However, you have not yet connected RMAN as TARGET to standby_new. In this case, you can execute RESYNC CATALOG FROM DB_UNIQUE_NAME standby_new. The primary database uses the connect identifier to make an Oracle Net connection to the standby database. When you later connect RMAN to the standby database, RMAN pushes the configuration from the recovery catalog to the mounted control file.

Note: If the database specified by CONFIGURE DB_UNIQUE_NAME is not registered in the recovery catalog, then RMAN implicitly registers it.

delalConf Configures an archived redo log deletion policy.

AUXNAME FOR DATAFILE
datafileSpec TO 'filename'
Configures the auxiliary filename for the specified target datafile to 'filename' (see Example 2-44). Specify CLEAR to unspecify the auxiliary filename.

If you are performing TSPITR or using DUPLICATE, then you can set AUXNAME to preconfigure the filenames for use on the auxiliary database without manually specifying the auxiliary filenames during the procedure.

For example, use this command during TSPITR if the datafiles are on raw disk and you must restore auxiliary datafiles to raw disk for performance reasons. Typically, you set the AUXNAME parameter in TSPITR for the datafiles of the SYSTEM and SYSAUX tablespaces and the tablespaces containing rollback or undo segments. Do not overlay files which are in use by the production database and can be discarded after TSPITR completes. In essence, the AUXNAME of a datafile is the location where TSPITR can create a temporary copy of it.

When renaming files with the DUPLICATE command, CONFIGURE AUXNAME is an alternative to SET NEWNAME. The difference is that after you set the AUXNAME the first time, you do not need to reset the filename when you issue another DUPLICATE command: the AUXNAME setting remains in effect until you issue CONFIGURE AUXNAME ... CLEAR. In contrast, you must reissue the SET NEWNAME command every time you execute the DUPLICATE command.

See Also: Oracle Database Backup and Recovery User's Guide to learn how to perform RMAN TSPITR, and Oracle Database Backup and Recovery User's Guide to learn how to duplicate a database with RMAN

backupConf Configures default backup options such as duplexing, optimization, excluding tablespaces, backup set sizes, and retention policies.
cfauConf Configures control file autobackup settings.

COMPRESSION ALGORITHM
'algorithm_name'
Specifies the algorithm that RMAN uses to create compressed backup sets. The default compression algorithm is BZIP2.

The supported algorithms are ZLIB and BZIP2. ZLIB is optimized for CPU efficiency. BZIP2 is optimized for maximum compression. BZIP2 consumes more CPU resource than ZLIB, but will usually produce more compact backups. The COMPATIBLE initialization parameter must be set to 11.0.0 or higher for ZLIB compression, which requires the Oracle Advanced Compression option.

Note: The V$RMAN_COMPRESSION_ALGORITHM view describes supported algorithms.

deviceConf Configures default backup settings for devices, such as the default backup device, channel configurations for devices, default backup types for each device, and parallelism.
ENCRYPTION Specifies transparent-mode encryption settings for the database or tablespaces.

This configuration applies unless overridden with the SET ENCRYPTION command. Options specified for an individual tablespace take precedence over options specified for the whole database.

See Also: "Encryption of Backup Sets" to learn about the different modes of backup encryption, and Oracle Database Advanced Security Administrator's Guide to learn about transparent data encryption


   ALGORITHM
   'algorithm_name'
Specifies the default algorithm to use for encryption when writing backup sets. Possible values are listed in V$RMAN_ENCRYPTION_ALGORITHMS. The CLEAR option resets the database to the default value.

   FOR DATABASE
   [ON | OFF | CLEAR]
Specifies whether to enable transparent encryption for the entire database. The options are as follows:
  • ON enables encryption for all database files.

  • OFF turns off encryption for all database files.

  • CLEAR restores the default setting of OFF.

Note: You must use the SET ENCRYPTION IDENTIFIED BY command to enable password encryption.


   FOR TABLESPACE
   tablespace_name
   [ON | OFF | CLEAR]
Specifies whether to enable transparent encryption for one or more tablespaces. Configured settings for a tablespace always override configuration set at the database level. The options are as follows:
  • ON enables encryption for the specified tablespace unless SET ENCRYPTION OFF FOR ALL TABLESPACES is used.

  • OFF disables encryption for the specified tablespace unless SET ENCRYPTION ON FOR ALL TABLESPACES is used.

  • CLEAR means that encryption for the specified tablespace is determined by the current default for the whole database.

Note: You must use the SET ENCRYPTION IDENTIFIED BY command to enable password encryption.


SNAPSHOT CONTROLFILE
NAME TO 'filename'
Configures the snapshot control file name and location to 'filename'. If you run CONFIGURE SNAPSHOT CONTROLFILE NAME CLEAR, then RMAN sets the snapshot control file name to its default.

The default value for the snapshot control file name is platform-specific and dependent on Oracle home. For example, the default on some UNIX systems is ?/dbs/snapcf_@.f. If you clear the control file name, and if you change Oracle home, then the default location of the snapshot control file changes as well.

The snapshot control file name is valid for this database only. Assume that you configure the snapshot control file name to a nondefault value on the primary database. If you use DUPLICATE to create a standby database, then the snapshot control file location on the standby database will be set to the default value. If desired, you can then configure the snapshot location on the standby database to a nondefault value.

See Also: Oracle Database Backup and Recovery User's Guide for more information about snapshot control files

forDbUniqueNameOption Creates an RMAN configuration in the recovery catalog for the database in a Data Guard environment specified by DB_UNIQUE_NAME. You can specify a single database with db_unique_name or use ALL for all databases in the recovery catalog that share the DBID of the target database (or DBID specified by the SET DBID command).

A recovery catalog is required when performing operations in a Data Guard environment. RMAN must be connected as TARGET to a mounted or open database (which can be a primary or standby database), or you must identify the target database with the SET DBID command. Thus, you can use this clause to create a persistent configuration for a standby database without connecting as TARGET to the standby or primary database. For example, you can create a configuration for a standby database before its creation so that the configuration applies after the database is created (see Example 2-46).

When you specify FOR DB_UNIQUE_NAME, RMAN directly updates the configuration metadata in the recovery catalog. When RMAN connects as TARGET to a database whose configurations were changed with FOR DB_UNIQUE_NAME, RMAN updates the mounted control file with the configuration metadata from the recovery catalog.

Note: It is possible to run CONFIGURE locally on a standby database and then run CONFIGURE FOR DB_UNIQUE_NAME for the same database while RMAN is not connected to this database as TARGET. In this case, the configuration in the recovery catalog overrides the configuration in the control file for the specific database.


delalConf

This subclause manages persistent configurations for archived redo log deletion policy.

Syntax Element Description
ARCHIVELOG DELETION POLICY Determines when archived redo log files are eligible for deletion.

The archived log deletion policy applies to all log archiving destinations, including the flash recovery area. Note that the policy does not apply to archived logs in backup sets.

Only archived redo logs in the flash recovery area are automatically deleted by the database. You can execute the BACKUP ... DELETE INPUT, DELETE ARCHIVELOG, or DELETE OBSOLETE commands to delete logs manually from log archiving destinations, including the recovery area. If FORCE is not specified on the deletion commands, then these deletion commands obey the archived log deletion policy. If FORCE is specified, then the deletion commands ignore the archived log deletion policy.

In the recovery area, the database retains logs eligible for deletion as long as possible. The database deletes the oldest logs first when disk space is required. When the recovery area is under disk pressure, the database may delete archived redo logs needed by Oracle Streams.

Note: The deletion policy does not apply to foreign archived redo logs, which are logs received by a logical standby database for a LogMiner session. These logs are transferred from a primary database, but unlike ordinary archived logs they have a different DBID. Foreign archived redo logs cannot be backed up or restored on a logical standby database.


   TO APPLIED ON
   [ALL] STANDBY
Specifies that archived redo logs are eligible for deletion if both of the following conditions are met:
  • The archived redo logs have been applied to the required standby databases.

  • The logs are not needed by the BACKED UP ... TIMES TO DEVICE TYPE deletion policy. If the BACKED UP policy is not set, then this condition is always met.

Which remote destinations are considered depends on the following criteria:

  • If you do not specify ALL, then archived logs are eligible for deletion after being applied to all mandatory remote destinations.

  • If you specify ALL, then archived logs are eligible after being applied or consumed on all remote destinations, whether mandatory or not.

    For example, standby database sby1 may be the only remote destination receiving logs, but other remote destinations may apply logs by referring to the same location on sby1. With ALL, sby1 marks the log on the primary database as consumed as soon as it is not required at sby1, but does not permit deletion of this log until it is applied or consumed by all other dependent remote destinations referring to the same location.

Note: It is invalid to specify the TO APPLIED clause in combination with either NONE or the TO SHIPPED clause.

See Also: Oracle Data Guard Concepts and Administration for details


   BACKED UP integer
   TIMES TO DEVICE
   TYPE deviceSpecifier
Specifies that archived redo logs are eligible for deletion if both of the following conditions are met:
  • The specified number of archived log backups exist on the specified device type.

  • The logs are not needed by the TO SHIPPED TO ... STANDBY or TO APPLIED ON ... STANDBY deletion policy. If neither standby deletion policy is set, then this condition is always met.

If you configure the deletion policy with this clause, then a BACKUP ARCHIVELOG command copies the logs unless integer backups already exist on the specified device type. If integer backups of the logs exist, then the BACKUP ARCHIVELOG command skips the logs. In this way, the archived log deletion policy functions as a default NOT BACKED UP integer TIMES clause on the BACKUP ARCHIVELOG command. You can override this deletion policy by specifying FORCE option on the BACKUP command.

See Also: deviceSpecifier

   TO NONE Disables the archived log deletion policy. This is the default setting.

Archived redo log files can be located inside or outside of the flash recovery area. Logs in any location can be deleted by manual commands. Only logs in the flash recovery area can be deleted automatically by the database.

When the deletion policy is set to NONE, RMAN considers archived redo log files as eligible for deletion if they meet both of the following conditions:

  • The archived redo log files, whether in the flash recovery area or outside of it, have been transferred to the required remote destinations specified by LOG_ARCHIVE_DEST_n.

  • The archived redo log files in the flash recovery area have been backed up at least once to disk or SBT or the logs are obsolete according to the backup retention policy.

    The backup retention policy considers logs obsolete only if the logs are not needed by a guaranteed restore point and the logs are not needed by Flashback Database. Archived redo logs are needed by Flashback Database if the logs were created later than SYSDATE-'DB_FLASHBACK_RETENTION_TARGET'.

For example, suppose that archived logs have been transferred to required remote destinations. The logs are obsolete according to the recovery window retention policy, but have not been backed up. In this case, the logs are eligible for deletion. Alternatively, suppose that the logs are obsolete and have been backed up to SBT, but have not been transferred to required remote destinations. In this case, the logs are not eligible for deletion.

If the deletion policy is set to NONE, and if you execute a deletion command for archived redo logs outside the flash recovery area, then RMAN obeys only the conditions specified on the deletion command.


   TO SHIPPED TO
   [ALL] STANDBY
Specifies that archived redo logs are eligible for deletion if both of the following conditions are met:
  • The archived redo logs have been transferred to the required remote destinations.

  • The logs are not needed by the BACKED UP ... TIMES TO DEVICE TYPE deletion policy. If the BACKED UP deletion policy is not set, then this condition is always met.

Which remote destinations are considered depends on the following criteria:

  • If you do not specify ALL, then the archived redo logs are eligible for deletion after transfer to mandatory remote destinations only.

  • If you specify ALL, then the logs are eligible for deletion after transfer to all remote destinations, whether mandatory or not.

Note: It is invalid to specify the TO SHIPPED clause in combination with NONE or the TO APPLIED clause.

See Also: Oracle Data Guard Concepts and Administration for details


backupConf

This subclause manages persistent configurations relating to the BACKUP command. One configuration is backup optimization. If you enable backup optimization, then RMAN does not back up a file to a device type if the identical file is already backed up on the device type.

Table 2-3 explains the criteria used by backup optimization to determine whether a file is identical and can potentially be skipped. The table also explains the algorithm that RMAN uses when backup optimization is enabled and it needs to determine whether to skip the backup of an identical file. If RMAN does not skip a backup, then it makes the backup exactly as specified.

Table 2-3 Backup Optimization Algorithm

File Type Criteria for an Identical File Backup Algorithm When Backup Optimization Is Enabled

Datafile

The datafile must have the same DBID, checkpoint SCN, creation SCN, and RESETLOGS SCN and time as a datafile already in a backup. The datafile must be offline-normal, read-only, or closed normally.

If a recovery window-based retention policy is enabled, then whether RMAN skips a datafile depends on the backup media.

For backups to tape, if the most recent backup is older than the recovery window, then RMAN takes another backup of a datafile even if a backup of an identical datafile exists. In this way, tapes can be recycled after they expire.

For backups to disk, RMAN skips the backup if an identical datafile is available on disk, even if that backup is older than the beginning of the recovery window. The window-based retention policy causes RMAN to retain the old backup for as long as it is needed.

If a retention policy is enabled with CONFIGURE RETENTION POLICY TO REDUNDANCY r, then RMAN skips backups only if at least n backups of an identical file exist on the specified device, where n=r+1.

If no retention policy is enabled, then RMAN skips a backup only if at least n backups of an identical file exist on the specified device. RMAN searches for values of n in this order of precedence (that is, values higher on the list override values lower on the list):

BACKUP ... COPIES n

SET BACKUP COPIES n

CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE ... TO n

n=1

Archived redo log

The archived redo log must have the same thread, sequence number, and RESETLOGS SCN and time as an archived log already in a backup.

RMAN skips a backup only if at least n backups of an identical file exist on the specified device. RMAN searches for values of n in this order of precedence (that is, values higher on the list override values lower on the list):

BACKUP ... COPIES n

SET BACKUP COPIES n

CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE ... TO n

n=1

Backup set

The backup set must have the same record ID and stamp as an existing backup set.

RMAN skips a backup only if at least n backups of an identical file exist on the specified device. By default, n=1. RMAN searches for other values of n in this order of precedence (that is, values higher on the list override values lower on the list):

BACKUP ... COPIES n

SET BACKUP COPIES n

n=1


Syntax Element Description

{ARCHIVELOG | DATAFILE}
BACKUP COPIES FOR DEVICE TYPE
deviceSpecifier TO integer
Specifies the number of copies of each backup set for DATAFILE (both datafiles and control files) or ARCHIVELOG files on the specified device type (see Example 2-41). You can create from 1 (default) to 4 copies.

RMAN can duplex backups to either disk or tape, but cannot duplex backups to tape and disk simultaneously. When backing up to tape, ensure that the number of copies does not exceed the number of available tape devices. Also, if COPIES is greater than 1, then the BACKUP_TAPE_IO_SLAVES initialization parameter must be enabled on the target database.

Control file autobackups are never duplexed. Also, duplexing is not permitted in the flash recovery area.

If duplexing is specified in the BACKUP command or in a SET BACKUP COPIES command, then the CONFIGURE setting is overridden.


BACKUP OPTIMIZATION
[ON | OFF | CLEAR]
Toggles backup optimization ON or OFF (default). Specify CLEAR to return optimization to its default value of OFF.

Backup optimization is enabled when all of the following conditions are met:

  • The CONFIGURE BACKUP OPTIMIZATION ON command has been run.

  • You run BACKUP DATABASE, BACKUP ARCHIVELOG with the ALL or LIKE options, BACKUP BACKUPSET ALL, BACKUP RECOVERY AREA, BACKUP RECOVERY FILES, or BACKUP DATAFILECOPY.

  • The RMAN job uses a channel of only one device type.

Optimization prevents RMAN from backing up a file to a device type if the identical file is already backed up on the device type. RMAN does not signal an error if backup optimization causes all files to be skipped during a backup. Note that the backup retention policy has an effect on which files backup optimization skips.

For two files to be identical, their content must be exactly the same, as described in Table 2-3. Note that when you create backup pieces on disk or on media managed by Oracle Secure Backup, optimization excludes undo data from the backup when the data does not belong to an active transaction.

Note: BACKUP ... DELETE INPUT deletes all specified archived redo log whether or not optimization would skip these files during a backup.

Note: You can override backup optimization with the FORCE option of the BACKUP command.

See Also: Oracle Database Backup and Recovery User's Guide for a description of how RMAN determines that it can skip the backup of a file


EXCLUDE FOR TABLESPACE
tablespace_name [CLEAR]
Excludes the specified tablespace from BACKUP DATABASE commands (see Example 2-43). Note that you cannot exclude the SYSTEM tablespace.

By default, each tablespace is not excluded, that is, the exclude functionality is disabled. The exclusion is stored as an attribute of the tablespace, not the individual datafiles, so the exclusion applies to any files that are added to this tablespace in the future. If you run CONFIGURE ... CLEAR on a tablespace after excluding it, then it returns to the default configuration of nonexclusion.

You can still back up an excluded tablespace by explicitly specifying it in a BACKUP command or by specifying the NOEXCLUDE option on a BACKUP DATABASE command.

MAXSETSIZE Specifies the maximum size of each backup set created on a channel. Use the CLEAR option to return MAXSETSIZE to the default value of UNLIMITED.

Note: This option is ignored by BACKUP AS COPY.

   TO sizeSpec Specifies the maximum size of each backup set as integer gigabytes, kilobytes, or megabytes.
   TO UNLIMITED Specifies no size limit for backup sets.
RETENTION POLICY Specifies a persistent, ongoing policy for backup sets and copies that RMAN marks as obsolete, that is, not needed and eligible for deletion.

As time passes, RMAN marks backup sets and copies as obsolete according to the criteria specified in the retention policy. RMAN automatically deletes obsolete backup sets and copies in the flash recovery area when space is needed. RMAN does not automatically delete obsolete files outside the flash recovery area: you must manually execute DELETE OBSOLETE to remove them.

For backups, the basic unit of the retention policy is a backup set (not a backup piece) or image copy. For example, BACKUP AS BACKUPSET COPIES 4 TABLESPACE users creates a single backup set that is duplexed into four identical backup pieces. The retention policy considers this as one backup, not four separate backups.

Note: Use the CLEAR option to return RETENTION POLICY to its default of REDUNDANCY 1.

   TO NONE Disables the retention policy feature. RMAN does not consider any backup sets or copies as obsolete.

   TO RECOVERY WINDOW
   OF integer DAYS
Specifies a time window in which RMAN should be able to recover the database.

The window stretches from the current time (SYSDATE) to the point of recoverability, which is the earliest date to which you want to recover. The point of recoverability is SYSDATE - integer days in the past.

Note: The REDUNDANCY and RECOVERY WINDOW options are mutually exclusive. Only one type of retention policy can be in effect at any time.

   TO REDUNDANCY integer Specifies that RMAN should retain integer full or level 0 backups of each datafile and control file. The default retention policy setting is REDUNDANCY 1.

If more than integer full or level 0 backups of a datafile or control file exist, then RMAN marks these extra files as obsolete. RMAN then determines the oldest of the retained backups and marks all archived redo logs and log backups older than this backup as obsolete. The DELETE OBSOLETE command removes obsolete datafile backups (full or incremental), control file backups, and archived log backups or image copies.

The following scenario illustrates how redundancy works in an incremental backup strategy. Assume that the redundancy level is 1. You run a level 0 database backup at noon Monday, a level 1 cumulative backup at noon on Tuesday and Wednesday, and a level 0 backup at noon on Thursday. Immediately after each daily backup you run a DELETE OBSOLETE. The Wednesday DELETE command does not remove the Tuesday level 1 backup because this backup is not redundant: the Tuesday level 1 backup could be used to recover the Monday level 0 backup to a time between noon on Tuesday and noon on Wednesday. However, the DELETE command on Thursday removes the previous level 0 and level 1 backups.

Note: The REDUNDANCY and RECOVERY WINDOW options are mutually exclusive. Only one type of retention policy can be in effect at any time.


cfauConf

This subclause creates persistent configurations relating to control file autobackups.

Syntax Element Description
CONTROLFILE AUTOBACKUP Controls the control file autobackup feature.

Note: You should enable control file autobackup feature when using RMAN without a recovery catalog.

   ON Specifies that RMAN should perform a control file autobackup in the following circumstances:
  • After every BACKUP or CREATE CATALOG command issued at the RMAN prompt.

  • Whenever a BACKUP command within a RUN block is followed by a command that is not BACKUP.

  • At the end of every RUN block if the last command in the block was BACKUP.

  • After structural changes for databases in ARCHIVELOG mode. The autobackup after structural changes does not occur for databases in NOARCHIVELOG mode.

    Structural changes include adding tablespaces, altering the state of a tablespace or datafile (for example, bringing it online), adding a new online redo log, renaming a file, adding a new redo thread, enabling or disabling Flashback Database, and so on. This type of autobackup, unlike autobackups that occur in the preceding circumstances, is only to disk. You can run CONFIGURE CONTROLFILE AUTOBACKUP FOR DEVICE TYPE DISK to set a nondefault disk location.

The first channel allocated during the backup or copy job creates the autobackup and places it into its own backup set; for post-structural autobackups, the default disk channel makes the backup. RMAN writes the control file and server parameter file to the same backup piece. After the control file autobackup completes, the database writes a message containing the complete path of the backup piece and the device type to the alert log.

The default location for the autobackup on disk is the flash recovery area (if configured) or a platform-specific location (if not configured). RMAN automatically backs up the current control file using the default format of %F. You can change the location and filename format with the CONFIGURE CONTROLFILE AUTOBACKUP FORMAT and SET CONTROLFILE AUTOBACKUP FORMAT commands.

You cannot configure RMAN to write the autobackup to multiple locations. To create multiple control file backups, you can make the last command in your backup job a BACKUP CURRENT CONTROLFILE FORMAT command, which will back up the control file to the specified FORMAT location and then execute an autobackup.

Note: The SET CONTROLFILE AUTOBACKUP FORMAT command, which you can specify either within a RUN block or at the RMAN prompt, overrides the configured autobackup format in the session only. The order of precedence is:

SET within a RUN block

SET at RMAN prompt

CONFIGURE CONTROLFILE AUTOBACKUP FORMAT

You can configure the autobackup format even when CONFIGURE CONTROLFILE AUTOBACKUP is set to OFF, but RMAN does not generate autobackups in this case. For RMAN to make autobackups, you must set CONFIGURE CONTROLFILE AUTOBACKUP to ON.

   OFF Disables the autobackup feature (default).

Any BACKUP command that includes datafile 1 automatically includes the current control file and server parameter file in the backup set. Otherwise, RMAN does not include these files.

   CLEAR Returns this configuration to its default setting of OFF.

   FORMAT FOR
   DEVICE TYPE
   deviceSpecifier
   TO formatSpec
Configures the default location and filename format for the control file autobackup on the specified device type (see Example 2-45).

By default, the format is %F for all devices. Any default format string specified with CONFIGURE must include the %F substitution variable. Use of any other substitution variable is an error. Specify CLEAR to return the format to the default %F.

If a flash recovery area is enabled, and if the format is the default '%F', then RMAN creates the autobackup in the recovery area in a directory named autobackup. Otherwise, the default autobackup location is an operating system-specific location (?/dbs on UNIX, Linux, and Windows).

The string # default in the output of the SHOW command indicates when RMAN is using the default format. If you manually configure the disk format to '%F', then RMAN creates the autobackups in the operating system-specific default location even though the recovery area is enabled. To change the format back to its default so that RMAN creates the autobackups in the recovery area, run CONFIGURE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK CLEAR.

The formatSpec can specify an Automatic Storage Management disk group. The following example configures a channel for an ASM disk group:

CONFIGURE CONTROLFILE AUTOBACKUP FOR DEVICE TYPE DISK TO '+dgroup1';

See Also: formatSpec for the semantics of the %F substitution variable


deviceConf

This subclause creates persistent configurations relating to channels and devices.

Names for Configured Channels

RMAN determines the names for configured channels. RMAN uses the following convention: ORA_devicetype_n, where devicetype refers to the user device type (such as DISK or sbt_tape) and n refers to the channel number. Channel names beginning with the ORA_ prefix are reserved by RMAN for its own use. You cannot manually allocate a channel with a name that begins with ORA_.

Note:

The sbt and sbt_tape device types are synonymous, but RMAN output always displays sbt_tape whether the input is sbt or sbt_tape.

RMAN names the first DISK channel ORA_DISK_1, the second ORA_DISK_2, and so on. RMAN names the first sbt channel ORA_SBT_TAPE_1, the second ORA_SBT_TAPE_2, and so on. When you parallelize channels, RMAN always allocates channels in numeric order, starting with 1 and ending with the parallelism setting (CONFIGURE DEVICE TYPE ... PARALLELISM n).

To run BACKUP or RESTORE jobs on specific configured channels, use the system-generated channel names. If you specify channel numbers in the CONFIGURE CHANNEL command (see the deviceConf clause), then RMAN uses the same numbers in the system-generated channel names.

Automatic channel allocation also applies to maintenance commands. If RMAN allocates an automatic maintenance channel, then it uses the same naming convention as any other automatically allocated channel.

Configured Channels in an Oracle RAC Environment

As long as the SYSDBA password for all Oracle RAC instances is the same, then you never need to put passwords in the CONNECT option of the ALLOCATE CHANNEL or CONFIGURE command. If you use a connect string of the form user@database, then RMAN automatically uses the same password that was used for the TARGET connection when the RMAN session was started (see Example 2-43).

Syntax Element Description

[AUXILIARY] CHANNEL [integer]
DEVICE TYPE deviceSpecifier
Specifies the standard or AUXILIARY channel that you are configuring or clearing, as well as the device type of the channel.

Note: Channels allocated with ALLOCATE CHANNEL within a RUN command override configured automatic channels.

Either configure a generic channel or specify a channel number, where integer is less than 255. See Example 2-43 for an illustration of numbered channels.

If AUXILIARY is specified, then this configuration is used only for channels allocated at the auxiliary instance. Specify configuration information for auxiliary channels if they require different parameters from the channels allocated at the target instance. If no auxiliary device configuration is specified, then RMAN configures any auxiliary channels using the target database device configuration.

You must specify at least one channel option. For example, you cannot issue a command such as CONFIGURE CHANNEL 2 DEVICE TYPE DISK, but you can issue a command such as CONFIGURE CHANNEL 2 DEVICE TYPE DISK MAXPIECESIZE 2500K.

For generic channels of a specified device type, a new command erases previous settings for this device type. Assume that you run these commands:

CONFIGURE CHANNEL DEVICE TYPE sbt MAXPIECESIZE 1G;
CONFIGURE CHANNEL DEVICE TYPE sbt FORMAT 'bkup_%U';

The second command erases the MAXPIECESIZE setting of the first command.

Note: RMAN does not simultaneously allocate automatic channels for multiple device types in the BACKUP command.

See Also: Oracle Database Backup and Recovery User's Guide to learn how configure automatic channels specified by channel number

   allocOperandList Specifies control options for the configured channel.

If you configure channels by using the nondefault CONNECT or PARMS options to create backups or copies, then you must either use the same configured channels or manually allocate channels with the same options to restore or crosscheck these backups.

Note that the FORMAT parameter can specify an Automatic Storage Management disk group. The following example configures a channel for an ASM disk group:

CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '+dgroup1';

See Also: allocOperandList

   CLEAR Clears the specified channel. For example, CONFIGURE CHANNEL 1 DEVICE TYPE DISK CLEAR returns only channel 1 to its default, whereas CONFIGURE CHANNEL DEVICE TYPE DISK CLEAR returns the generic disk channel to its default. Note that you cannot specify any other channel options (for example, PARMS) when you specify CLEAR.

DEFAULT DEVICE TYPE TO
deviceSpecifier
Specifies the default device type for automatic channels. By default, DISK is the default device type. CLEAR returns the default device type to DISK.

By default, the BACKUP command only allocates channels of the default device type. For example, if you configure automatic channels for DISK and sbt and set the default device type to sbt, then RMAN only allocates tape channels when you run the BACKUP DATABASE command. You can override this behavior either by manually allocating channels in a RUN command, or by specifying DEVICE TYPE on the BACKUP command itself (see Example 2-41).

The RESTORE command allocates automatic channels of all configured device types, regardless of the default device type. The RESTORE command obeys the PARALLELISM setting for each configured device type.


DEVICE TYPE
deviceSpecifier
Specifies the device type (disk or sbt) to which to apply the settings specified in this CONFIGURE command. The CLEAR option resets backup type and parallelism settings for this device to their defaults.

If you run the CONFIGURE DEVICE TYPE command to configure default settings for a device type and do not run CONFIGURE CHANNEL for this device type, then RMAN allocates all channels without other channel control options. Assume that you configure the sbt device and run a backup as follows:

CONFIGURE DEVICE TYPE sbt PARALLELISM 1;
BACKUP DEVICE TYPE sbt DATABASE;

In effect, RMAN does the following when executing this backup:

RUN 
{
  ALLOCATE CHANNEL ORA_SBT_TAPE_1 DEVICE TYPE sbt;
  BACKUP DATABASE;
}

   BACKUP TYPE TO
   [[COMPRESSED]
   BACKUPSET | COPY]
Configures the default backup type for disk or tape backups. For SBT devices the COPY option is not supported. The default for disk is BACKUPSET.

If BACKUP TYPE is set to BACKUPSET, then the BACKUP command always produces backup sets regardless of which media the backup is created on. With the COMPRESSED option, the backup sets produced use binary compression.

The default location for disk backups is the flash recovery area, if one is configured; otherwise, RMAN stores backups in a platform-specific location. The default format for backup filenames is %U.

   PARALLELISM integer Configures the number of automatic channels of the specified device type allocated for RMAN jobs. By default, PARALLELISM is set to 1.

Note: The CONFIGURE ... PARALLELISM parameter specifies channel parallelism, that is, the number of channels that RMAN allocates during backup and restore operations. The RECOVERY_PARALLELISM initialization parameter specifies the number of processes used in instance recovery.

Suppose you set PARALLELISM for disk backups to 2 (see Example 2-42). If you set the default device type as disk, then RMAN allocates two disk channels when you run BACKUP DATABASE at the RMAN prompt. RMAN always allocates the number of channels set by PARALLELISM, although it may use only a subset of these channels.

Note: If you configure n manually numbered channels, then the PARALLELISM setting can be greater than or less than n. For example, you can manually number 10 automatic channels and configure PARALLELISM to 2 or 12.

To change the parallelism for a device type to n, run a new CONFIGURE DEVICE TYPE ... PARALLELISM n command. For example, you can change configure PARALLELISM to 3 for sbt and then change it to 2 as follows:

CONFIGURE DEVICE TYPE sbt PARALLELISM 3;
CONFIGURE DEVICE TYPE sbt PARALLELISM 2;

Examples

Example 2-40 Configuring Device and Backup Options

This example configures channels of device type DISK and sbt and sets the default device type as sbt. The example also enables backup optimization and configures a recovery windows of two weeks.

CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '/disk1/backups/%U';
CONFIGURE CHANNEL DEVICE TYPE sbt PARMS 'ENV=(OB_DEVICE_1=tape1)';
CONFIGURE DEFAULT DEVICE TYPE TO sbt;
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 14 DAYS;

Example 2-41 Overriding the Default Device Type

This example configures duplexing to 2 for DISK backups of datafiles and control files (control file autobackups on disk are a special case and are never duplexed), then configures sbt as the default device.

CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 2;
CONFIGURE CHANNEL DEVICE TYPE sbt PARMS 'ENV=(OB_DEVICE_1=tape1)';
CONFIGURE DEFAULT DEVICE TYPE TO sbt;

The first BACKUP command backs up the archived redo logs on the default sbt channel. The second BACKUP command backs up the database to disk locations. Because duplexing is enabled for disk backups, two copies of each output backup set are created.

BACKUP ARCHIVELOG ALL;
BACKUP DEVICE TYPE DISK 
  DATABASE
  FORMAT '/disk1/db_backup_%U','/disk2/db_backup_%U';

Example 2-42 Configuring Automatic Channels Across File Systems

This example configures automatic disk channels across two file systems:

CONFIGURE DEVICE TYPE DISK PARALLELISM 2;
CONFIGURE CHANNEL 1 DEVICE TYPE DISK FORMAT '/disk1/%U';
CONFIGURE CHANNEL 2 DEVICE TYPE DISK FORMAT '/disk2/%U';

Because PARALLELISM is set to 2, the following command divides the output data between two file systems:

BACKUP DEVICE TYPE DISK
  DATABASE PLUS ARCHIVELOG;

The following LIST command shows how the datafile backup was parallelized:

RMAN> LIST BACKUPSET 2031, 2032;
 
List of Backup Sets
===================
 
BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
2031    Full    401.99M    DISK        00:00:57     19-JAN-07
        BP Key: 2038   Status: AVAILABLE  Compressed: NO  Tag: TAG20070119T100532
        Piece Name: /disk1/24i7ssnc_1_1
  List of Datafiles in backup set 2031
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  1       Full 973497     19-JAN-07 /disk3/oracle/dbs/t_db1.f
  5       Full 973497     19-JAN-07 /disk3/oracle/dbs/tbs_112.f
 
BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
2032    Full    133.29M    DISK        00:00:57     19-JAN-07
        BP Key: 2039   Status: AVAILABLE  Compressed: NO  Tag: TAG20070119T100532
        Piece Name: /disk2/25i7ssnc_1_1
  List of Datafiles in backup set 2032
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  2       Full 973501     19-JAN-07 /disk3/oracle/dbs/t_ax1.f
  3       Full 973501     19-JAN-07 /disk3/oracle/dbs/t_undo1.f
  4       Full 973501     19-JAN-07 /disk3/oracle/dbs/tbs_111.f

Example 2-43 Configuring Automatic Channels in an Oracle Real Application Clusters (Oracle RAC) Configuration

This example assumes an Oracle RAC database with two nodes. Oracle Secure Backup is the media manager. Tape drive tape1 is directly attached to node1, while tape drive tape2 is directly attached to node2. The example configures an automatic SBT channel for each cluster node.

This example illustrates channel connections to Oracle RAC instances node1 and node2. For both channel connections, RMAN uses the same username and password that were entered for the target database connection.

CONFIGURE DEVICE TYPE sbt PARALLELISM 2;
CONFIGURE DEFAULT DEVICE TYPE TO sbt;
CONFIGURE CHANNEL 1 DEVICE TYPE sbt CONNECT '@node1'
  PARMS 'ENV=(OB_DEVICE=tape1)';
CONFIGURE CHANNEL 2 DEVICE TYPE sbt CONNECT '@node2'
  PARMS 'ENV=(OB_DEVICE=tape2)';

Example 2-44 Configuring Auxiliary Filenames

This example uses CONFIGURE AUXNAME to specify new filenames for the datafiles. The DUPLICATE command duplicates a database to a remote host with a different directory structure.

# set auxiliary names for the datafiles 
CONFIGURE AUXNAME FOR DATAFILE 1 TO '/oracle/auxfiles/aux_1.f'; 
CONFIGURE AUXNAME FOR DATAFILE 2 TO '/oracle/auxfiles/aux_2.f'; 
CONFIGURE AUXNAME FOR DATAFILE 3 TO '/oracle/auxfiles/aux_3.f'; 
CONFIGURE AUXNAME FOR DATAFILE 4 TO '/oracle/auxfiles/aux_4.f'; 

RUN
{  
  ALLOCATE AUXILIARY CHANNEL dupdb1 TYPE DISK;
  DUPLICATE TARGET DATABASE TO dupdb 
  LOGFILE
    GROUP 1 ('?/dbs/dupdb_log_1_1.f', 
             '?/dbs/dupdb_log_1_2.f') SIZE 4M,
    GROUP 2 ('?/dbs/dupdb_log_2_1.f', 
             '?/dbs/dupdb_log_2_2.f') SIZE 4M REUSE; 
}
# Un-specify the auxiliary names for the datafiles so that they are not 
# overwritten by mistake:
CONFIGURE AUXNAME FOR DATAFILE 1 CLEAR; 
CONFIGURE AUXNAME FOR DATAFILE 2 CLEAR; 
CONFIGURE AUXNAME FOR DATAFILE 3 CLEAR; 
CONFIGURE AUXNAME FOR DATAFILE 4 CLEAR;

Example 2-45 Specifying the Default Format for Control File Autobackup

The following example enables the autobackup feature and configures the default autobackup format for the DISK and sbt devices:

CONFIGURE CONTROLFILE AUTOBACKUP ON; 
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/disk2/%F';
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE sbt TO 'cf_auto_%F';

Example 2-46 Creating Configurations for Standby Databases

Assume that primary database prod is associated with two standby databases with the DB_UNIQUE_NAME names dgprod3 and dgprod4. Assume that you start RMAN and connect to prod as TARGET and connect to a recovery catalog. The following commands configure the default device type for databases dgprod3 and dgprod4.

CONFIGURE DEFAULT DEVICE TYPE TO sbt
  FOR DB_UNIQUE_NAME dgprod3;
CONFIGURE DEVICE TYPE sbt PARALLELISM 2
  FOR DB_UNIQUE_NAME dgprod3;
CONFIGURE DEFAULT DEVICE TYPE TO DISK
  FOR DB_UNIQUE_NAME dgprod4;

The control files of the two standby databases are updated with the configuration only after the reverse resynchronization from the recovery catalog to the control file, which occurs the first time that the user connects to dgprod3 and dgprod4.

The following SHOW command displays the persistent device type configurations for the database whose unique name is dgprod3:

RMAN> SHOW DEVICE TYPE FOR DB_UNIQUE_NAME dgprod3;
RMAN configuration parameters for database with db_unique_name DGPROD3 are:

CONFIGURE DEVICE TYPE 'SBT_TAPE' PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default

The following SHOW command displays the persistent configurations for all databases known to the recovery catalog whose DBID is 3257174182 (the value specified by the preceding SET DBID command):

SHOW ALL FOR DB_UNIQUE_NAME ALL;

Example 2-47 Optimizing Backups

This scenario illustrates the backup optimization behavior described in Table 2-3. Assume that backup optimization is disabled. At 9 a.m., you back up three copies of all existing archived logs to tape. Note that the BACKUP_TAPE_IO_SLAVES initialization parameter must be true when duplexing backups to tape.

BACKUP DEVICE TYPE sbt COPIES 3 ARCHIVELOG ALL;

At 11 a.m., you enable backup optimization:

CONFIGURE BACKUP OPTIMIZATION ON;

At noon, you run the following archived redo log backup:

BACKUP DEVICE TYPE sbt COPIES 2 ARCHIVELOG ALL;

Starting backup at 19-JAN-07
current log archived
using channel ORA_SBT_TAPE_1
skipping archived log file /d1/db1r_605ab325_1_34_612112605.arc; already backed up 3 time(s)
skipping archived log file /d1/db1r_605ab325_1_35_612112605.arc; already backed up 3 time(s)
skipping archived log file /d1/db1r_605ab325_1_36_612112605.arc; already backed up 3 time(s)
skipping archived log file /d1/db1r_605ab325_1_37_612112605.arc; already backed up 3 time(s)
skipping archived log file /d1/db1r_605ab325_1_38_612112605.arc; already backed up 3 time(s)
skipping archived log file /d1/db1r_605ab325_1_39_612112605.arc; already backed up 3 time(s)
channel ORA_SBT_TAPE_1: starting archived log backup set
channel ORA_SBT_TAPE_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=40 RECID=170 STAMP=612270506
channel ORA_SBT_TAPE_1: starting piece 1 at 19-JAN-07
channel ORA_SBT_TAPE_1: finished piece 1 at 19-JAN-07 with 2 copies and tag TAG20070119T110827
piece handle=2hi7t0db_1_1 comment=API Version 2.0,MMS Version 10.1.0.0
piece handle=2hi7t0db_1_2 comment=API Version 2.0,MMS Version 10.1.0.0

In this case, the BACKUP ... COPIES setting overrides the CONFIGURE ... COPIES setting, so RMAN sets n=2. RMAN skips the backup of a log only if at least two copies of the log exist on the sbt device. Because three copies of each log exist on sbt of all the logs generated on or before 9 a.m., RMAN skips the backups of these logs. However, RMAN backs up two copies of all logs generated after 9 a.m. because these logs have not yet been backed up to tape.