RMAN(Script Overview)

8/16/2019 RMAN(Script Overview)

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Introduction to Recovery Manager 1. Recovery Manager (RMAN) is an Oracleutility that can back up, restore, and

recover database files. he product is a feature of theOracle database server and does not

re!uire separate installation. Recovery Manager is a client"server application that uses

database server sessions to perfor# backup and recovery.

About Recovery Manager (RMAN)

Recovery Manager (RMAN) is an Oracle utility that can back up, restore, and recover

database files. he product is a feature of the Oracle database server and does not re!uire

separate installation.

Recovery Manager is a client"server application that uses database server sessions to

perfor# backup and recovery. $t stores #etadata about its operations in the control file of

the target database and, optionally, in a recovery catalog sche#a in an Oracle database.

%ou can invoke RMAN as a co##and&line e'ecutable fro# the operating syste# pro#pt

or use so#e RMAN features through the nterprise Manager *$.

Why Use RMAN?

Most production database syste#s i#pose stringent re!uire#ents on backup and recovery.

As a +A in charge of backup and recovery, you #ust-

• Manage the complexity of backup and recovery operations

• Minimize the possibility of human error

• Make backups scalable and reliable

• Utilize all available media hardware

• Make backups proportional to the size of transactional changes,not to the size of database


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• Make recovery time proportional to the amount of data recovered

%ou have to basic #ethods for perfor#ing these backup and recovery tasks on an Oracle

release /.0 or higher database-

• Using operating system commands to perform backup and restoreoperations, and SQL or SQL!lus statements to perform recovery

• Using "ecovery Manager for backup, restore, and recovery

Note :-

"M#$ was introduced in %racle release &'( and is not compatible with

%racle databases prior to release &'('

hy use one #ethod rather than the other2 As illustrated in 3igure 1&1, RMAN uses

server sessions to perfor# backup and recovery operations and stores #etadata in a

repository. RMAN auto#ates backup and recovery, hereas the useranaged #ethod

re!uires you to keep track of all database files and backups. 3or e'a#ple, instead of

re!uiring you to locate backups for each datafile, copy the# to the correct place using

operating syste# co##ands, and choose hich logs to apply, RMAN #anages these tasks

auto#atically.

he advantage of using RMAN is especially true if you use Oracle Managed 3iles. hen

you let Oracle na#e and #anage your datafiles, control files, and online redo logs, the

syste# beco#es easier to use. On the other hand, it #ay be harder for you to keep track of

the filena#es of the various database files because you have not na#ed the# yourself.

RMAN users do not suffer fro# this proble# because RMAN handles all record keeping.

Figure 1-1 Comparison of RMAN Automated and User-Managed Procedures

http://docs.oracle.com/cd/B10501_01/server.920/a96566/rcmintro.htm#452884http://docs.oracle.com/cd/B10501_01/server.920/a96566/rcmintro.htm#452884


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Overview of the RMAN Environent

he RMAN environ#ent consists of the utilities and databases that play a role in a backup

and recovery strategy. A typical RMAN setup utili4es the folloing-

• "M#$ executable

• )arget database

• "ecovery catalog database

• Media management software

Of these co#ponents, only the RMAN e'ecutable and target database are re!uired.RMAN auto#atically stores its #etadata in the target database control file, so the recovery

catalog database is optional. Nevertheless, #aintaining a recovery catalog is strongly

encouraged. $f you create a catalog on a separate #achine, and if the production #achine

fails co#pletely, then you have all the restore and recovery infor#ation you need in the

catalog.

About the RMAN E!ecutab"e

he RMAN e'ecutable is auto#atically included ith the Oracle softare installation. $ts

location is platfor#&specific and is typically located in the sa#e place as the other Oracle

e'ecutables. On *ni' syste#s, for e'a#ple, the RMAN e'ecutable is located

in $ORACLE_HOME/bin.


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o start the e'ecutable, si#ply enter the filena#e on the co##and line. 3or e'a#ple, on a

*N$5 syste#, enter-

% rman

About the #arget $atabase

he target database is the database that RMAN is backing up, restoring, or recovering.

%ou can use a single recovery catalog in con6unction ith #ultiple target databases. 3or

e'a#ple, assu#e that your data center contains 10 databases of varying si4es. %ou can use

a single recovery catalog located in a different data center to #anage the #etadata fro# all

of these databases.

About the RMAN Re%ository

he RMAN repository is a set of #etadata that RMAN uses to store infor#ation about the

target database and its backup and recovery operations. A#ong other things, RMAN

stores infor#ation about-

• *ackup sets and pieces

• +mage copies including archived redo logs-

• !roxy copies

• )he target database schema

• !ersistent con.guration settings

%ou can access this #etadata by issuing LIST, REPORT, and SHOW co##ands in the RMAN

interface, or by using SELECT state#ents on the catalog vies (only if you use a recovery

catalog). 3igure 1&7illustrates ho RMAN issues lists and reports.



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Figure 1-2 RMAN Lists and Reports

%ou can either create a recovery catalog in hich to store the repository, or let RMAN

store the repository e'clusively in the target database control file. 3igure 1&8 depicts

RMAN using a recovery catalog.

Figure 1-3 RMAN with ptiona! Reco"er# Cata!og



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Comparison Between RMAN and User-Managed Methods $-

Recovery Manager User&Managed Method

*ses a #edia #anage#ent A9$ so that RMAN

orks sea#lessly ith third&party #edia

#anage#ent softare. More than 70 vendorssupport the A9$.

+oes not have support of a published A9$.

hen backing up online files, RMAN rereadsfractured data blocks to get a consistent read. %ou

do not need to place online tablespaces in backup#ode hen perfor#ing backups.

Re!uires placing online tablespaces in backup#ode before backing the# up, and then taking

the tablespaces out of this #ode after the backupis co#plete. :erious database perfor#ance and#anageability proble#s can occur if you neglect

to take tablespaces out of backup #ode after an

online backup is co#plete.

9erfor#s incre#ental backups, hich back up

only those data blocks that changed after a previous backup. %ou can recover the database

using incre#ental backups, hich #eans that youcan recover aNOARCHIVELOG database. ;oever,

you can only take incre#ental backups of

a NOARCHIVELOG database after a consistent

shutdon.

acks up all blocks, not 6ust the changed blocks.

+oes not allo you to recovera NOARCHIVELOGdatabase.


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O#its never&used blocks fro# datafile backups sothat only data blocks that have been ritten to are

included in a backup.

$ncludes all data blocks, regardless of hetherthey contain data.

*ses the repository to report on crucial

infor#ation, including-

• +atabase sche#a at a specified ti#e

•

hich files need a backup

• hich files have not had a backup in a

specified nu#ber of days

• hich backups can be deleted because

they are redundant or cannot be used for

recovery

•


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then issuing operating syste# co##ands in parallel.

ests hether files can be backed up or restored

ithout actually perfor#ing the backup or restore.

Re!uires you to actually restore backup files

before you can perfor# a trial recovery of the

backups.

9erfor#s archived log failover auto#atically. $f

RMAN discovers a corrupt or #issing log duringa backup, then it considers all logs and log copies

listed in the repository as alternative candidates

for the backup.


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efore getting into the configr! co##and, lets first take a look at our default settings by

using the show co##and-RMAN" SHOW ALL;

RMAN configra#ion aram!#!r ar!&CON'IG(RE RETENTION POLIC) TO RE*(N*ANC) +, - .!fa#CON'IG(RE 0AC1(P OPTIMI2ATION O'', - .!fa#CON'IG(RE *E'A(LT *EVICE T)PE TO *IS1, - .!fa#CON'IG(RE CONTROL'ILE A(TO0AC1(P O'', - .!fa#CON'IG(RE CONTROL'ILE A(TO0AC1(P 'ORMAT 'OR *EVICE T)PE *IS1 TO 3%'3, - .!fa#CON'IG(RE *EVICE T)PE *IS1 PARALLELISM +, - .!fa#CON'IG(RE *ATA'ILE 0AC1(P COPIES 'OR *EVICE T)PE *IS1 TO +, - .!fa#CON'IG(RE ARCHIVELOG 0AC1(P COPIES 'OR *EVICE T)PE *IS1 TO +, - .!fa#CON'IG(RE MA4SETSI2E TO (NLIMITE*, - .!fa#CON'IG(RE SNAPSHOT CONTROL'ILE NAME TO3/5+/a/orac!/ro.c#/+56765/.b/nacf_TARG*06f3, - .!fa#

3ro# the above listing, you can see that the RMAN allos you to set default values forso#e of the folloing-

• he default retention policy. his deter#ines hich backups and copies are

eligible for deletion because they are no longer needed.

• urning ON and O33 backup opti#i4ation. ackup opti#i4ation eli#inates

duplicate backups of identical datafiles (like those associated ith a read&

only tablespace) and archived redo logs.

• A default device type for RMAN 6obs, (disk or tape [sbt])

• he default for auto#ated backups of the control file to ON or O33. %ou can

also control the default for#at of the control file backup output files and the

default device on hich to create these backups.

• he nu#ber of channels (for paralleli4ation) that are auto#atically allocated

hen perfor#ing auto#ated backup and recovery"restore 6obs.

• A tablespace e'clusion policy to configure specific tablespaces to be

e'cluded during full database backup operations. $f there are no tablespacee'clusion policies defined, nothing ill be displayed by the 8o9

a co##and.

• he #a'i#u# si4e for any given backup piece and the si4e of any backup set

hen perfor#ing auto#ated backups.


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• he default filena#e for the snapshot controlfile.

his article ill provide detailed infor#ation on all of these RMAN configuration

para#eters and ho they can be defined.

Using Substitution Variables

RMAN can #ake use of substitution variables in creating for#at strings to generate

filena#es. ithout due care, non&uni!ue filena#es can be generated and, under certain

circu#stances, this can cause backup data to be overritten and therefore lost. :o becareful@ this is not a bug ith Oracle, but rather a usage error.

Format Description

%specifies the backup piece number ithin the backup set. his value starts at 1 for each

backup set and is incre#ented by 1 as each backup piece is created.

%

specifies the backup set number . his nu#ber is a counter in the control file that is

incre#ented for each backup set. he counter value starts at 1 and is uni!ue for the lifeti#eof the control file. $f you restore a backup control file, then duplicate values can result. Also,

initiali4es the counter back to 1.

%. specifies the database na#e.

%n

specifies the database name, padded on the right ith ' characters to a total length of /

characters. 3or e'a#ple, if 9RO+1 is the database na#e, then 9RO+1''' is the paddeddatabase na#e.

%#

specifies the backup set timestamp, hich is a B&byte value derived as the nu#ber of

seconds elapsed since a fi'ed reference ti#e. he co#bination of Cs and Ct can be used tofor# a uni!ue na#e for the backup set.

%specifies an /&character na#e constituted by co#pressed representations of the backup set

nu#ber and the ti#e the backup set as created.

%c

(Oracle/i or higher) & specifies the copy nu#ber of the backup piece ithin a set of

duple'ed backup pieces. $f you did not issue the set duple' co##and, then this variable ill be 1 for regular backup sets and 0 for pro'y copies. $f you issued set duple', the variable

identifies the copy nu#ber- 1, 7, 8, or B.

%(

(Oracle/i or higher) & specifies a convenient shorthand for CuDCpDCc that guarantees

uni!ueness in generated backup filena#es. $f you do not specify a for#at, RMAN uses C* by default. C* is the default in Oracle/i.


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Using the configure Comman to Clear Values

efore discussing each of the RMAN configuration para#eters in detail, lets first take a

look at ho to clear values. (:etting these configuration para#eters to their default values)

>ike setting an RMAN configuration para#eter, you use the configr! co##and, but ill

use the clear option.

o set the MA4SETSI2E para#eter back to its default value of *N>$M$+-

RMAN" configure maxsetsize clear;;ere is a list of co##ands that clear several RMAN settings back to their default values-RMAN" CONFIG!" !"#"N#ION $OLIC% CL"A!;RMAN" CONFIG!" &AC'$ O$#I(I)A#ION CL"A!;RMAN" CONFIG!" *"FAL# *"+IC" #%$" CL"A!;RMAN" CONFIG!" CON#!OLFIL" A#O&AC'$ CL"A!;RMAN" CONFIG!" CON#!OLFIL" A#O&AC'$ FO!(A# FO! *"+IC" #%$" *IS' CL"A!;RMAN" CONFIG!" CON#!OLFIL" A#O&AC'$ FO!(A# FO! *"+IC" #%$" S CL"A!;RMAN" CONFIG!" *"+IC" #%$" *IS' CL"A!;RMAN" CONFIG!" *A#AFIL" &AC'$ CO$I"S FO! *"+IC" #%$" *IS' CL"A!;RMAN" CONFIG!" *A#AFIL" &AC'$ CO$I"S FO! *"+IC" #%$" S CL"A!;RMAN" CONFIG!" A!CHI+"LOG &AC'$ CO$I"S FO! *"+IC" #%$" *IS' CL"A!;RMAN" CONFIG!" A!CHI+"LOG &AC'$ CO$I"S FO! *"+IC" #%$" S CL"A!;RMAN" CONFIG!" CHANN"L *"+IC" #%$" *IS' CL"A!;RMAN" CONFIG!" CHANN"L *"+IC" #%$" S CL"A!;RMAN" CONFIG!" (A,S"#SI)" CL"A!;RMAN" CONFIG!" SNA$SHO# CON#!OLFIL" NA(" CL"A!;RMAN" - CONFIG!" ",CL*" FO! #A&L"S$AC" S"!S.!"A*.#&S;

R!"!N"#ON $O%#C&

*sed to control ho long RMAN ill keep backups. his can be configured by the

Enu#berE of backups taken, or by the nu#bers of EdaysE to keep. ;ere is an e'a#ple of

both-CONFIG!" !"#"N#ION $OLIC% #O !"*N*ANC% /;

CONFIG!" !"#"N#ION $OLIC% #O !"CO+"!% WIN*OW OF 0 *A%S;


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Note that hen configuring a retention policy, RMAN ill not cause backups to be

auto#atically deleted. he retention policy ill, hoever, #ark backups as O:O>

that have fallen outside the retention period. RMAN co##ands like EREPORT O0SOLETEE

and E*ELETE O0SOLETEE ill ork ith these obsolete backups.

$f back up your database infre!uently, you probably ill prefer a redundancy policy that is

stated in ter#s of nu#ber of backups rather than backups later than n days old. $n this

case, you ould use the re1un1anc2 para#eter as follos-

RMAN" CONFIG!" !"#"N#ION $OLIC% #O !"*N*ANC% 0;

3inally, if you do not ant to use a retention policy, si#ply use-RMAN" CONFIG!" !"#"N#ION $OLIC% #O NON";

'AC(U$ O$"#M#)A"#ON

*sed to enable or disable backup opti#i4ation. ackup file opti#i4ation can assist in

reducing the space used to backup the database. hen perfor#ing an RMAN backup, a

check is done on the file before backup to see if the file already e'ists in a backupset ith

the sa#e infor#ation- (dbid, checkpoint, and resetlogs data).

3or archive logs, the sa#e file #eans the sa#e dbid, thread, se!uence, and resetlogs data.$f the +> $N9* option is used, RMAN deletes all the files that ould have been

backed up, even hen the file is not included due to file opti#i4ation.

he to possible values for backup opti#i4ation is ON and O33 as shon in the

folloing e'a#ple synta'-

CONFIG!" &AC'$ O$#I(I)A#ION OFF;

CONFIG!" &AC'$ O$#I(I)A#ION ON;

*se caution hen enabling backup opti#i4ation if you use a #edia #anager that has an

e'piration policy. he #edia #anager can e'pire tapes containing backups (using its

#edia control softare), and RMAN ill not #ake ne backups because of opti#i4ation.

One ay to protect fro# this is to run


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e'a#ple, consider perfor#ing a backup ith opti#i4ation enabled and a retention period

of 8 days. RMAN ill only co#pare the datafile ith backup sets ithin the 8 day period

& even if the datafile it is about to backup hasnt changed ithin that 8 days.

D!FAU%" D!V#C! "&$!


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CONFIG!" CON#!OLFIL" A#O&AC'$ OFF;

hen the 3$> A*OA and the :93$> (if the database as started ith

an :93$>) to the sa#e backup piece. After the 3$> A*OA


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docu#ented (above). hen 3$> A*OA and :93$>, (if the database as started ith an spfile), are includedauto#atically hen datafile 1 is backed up.


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>>$:M to 7 or even 17.

DA"A'AS! +an ARC,#V!%O-. 'AC(U$ CO$#!S

:pecifies the nu#ber of copies of each backup set for +AA3$> (both datafiles and

control files) or ARO files on the specified device type, fro# 1 (default) to B. $f

duple'ing is specified in the 0AC1(P co##and or in a SET 0AC1(P COPIES co##and, then

the CON'IG(RE setting is overridden.


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;ere is the general synta'-

?ARCHIVELOG> *ATA'ILE@

0AC1(P COPIES 'OR *EVICE T)PE .!ic!S!cifi!r TO in#!g!r,

NO"!*


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aocO!ran.Li# / S!cifi! con#ro o#ion for #8! / / aoca#!. c8ann! /


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RMAN" CONFIG!" CHANN"L 6 *"+IC" #%$" *IS' FO!(A#78ora3ac4u568rman8O!A9/:83ac4u5.13.1.S.s.$.5.#.t7 (A,$I"C"SI)" 6:/9 operations. he RA para#eter

specifies units of bytes"second. est to find a value that i#proves perfor#ance of your

!ueries hile still letting RMAN co#plete the backup in a reasonable a#ount of ti#e. Note

that RATE is not designed to increase backup throughput, but to decrease backup throughputso that #ore disk bandidth is available for other database operations.

NO"!* he


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database device configuration. $t is not necessary to specify configuration infor#ation for

au'iliary channels unless they re!uire different para#eters fro# the target channels.

NO"!* 3or generic channels of a specified device type, a ne co##and erases previous

settings for this device type. Assu#e that you run these co##ands-CONFIG!" CHANN"L *"+IC" #%$" s3t (A,$I"C"SI)" 6G;CONFIG!" CHANN"L *"+IC" #%$" s3t !A#" 6B::';

he second co##and erases the MA59$


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docu#entation states that it li#its the si4e of a backup set, it see#s to place li#its on the

datafile si4es & even though $ a# using backup sets and not i#age copies. 3or e'a#ple, $

have set MA5::$ to H00# and atte#pted to backup a database, only to get the error-

RMAN:5+Q& .a#afi! or .a#afi!coB arg!r #8an SETSI2E& fi!- +/+5/a/ora.a#a/TARG*0/!r5+6.bf

he file (users01.dbf) is larger than H00M but the backupset is considerably s#aller thanthat (there is very little data in there at present). he Oracle docu#entation states that

MA5::$ li#its the si4e of the backupsets, NO the si4e of the datafiles hich can be

backed&up. All $ can say, is that Oracle states that this is e'pected behavior, and $ think it isa bug in the docu#entation.

$f you ant to set the value backup to its default, use-

RMAN" CONFIG!" (A,S"#SI)" CL"A!;

SNA$S,O" CON"RO%F#%!

A snapshot control file is created by RMAN during the backup process that serves as a

point&in&ti#e copy of the database control file. his ill ensure that that backups being

taken is consistent to a given point in ti#e. 3or e'a#ple, if you add a datafile ortablespace to a database after the backup has started, (assu#ing an online backup and

before the backup has ended), that datafile and"or tablespace ill not be included in the

backup. $t is so#eti#es re!uired that the location and na#e of the snapshot control file be

changed fro# its default.

o set the snapshot control file to a different location (and na#e) use the folloing-

RMAN" CONFIG!" SNA$SHO# CON#!OLFIL" NA(" #O78ora3ac4u58rman8O!A9/:8scontrolfile?ctl7;

NO"!* he default value for the snapshot control file na#e is platfor#&specific anddependent on the Oracle ho#e. 3or e'a#ple, the default on so#e *N$5 syste#

is/.b/nacf_6f. $f you clear the control file na#e, and you change the Oracle ho#e,

then the default location of the snapshot control file changes as ell.


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RMAN(Script Overview)

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