官方文档 恢复备份指南二 Getting Started with RMAN

也可以用操作系统验证登录：

%rman
RMAN>CONNECTTARGET/

connectedtotargetdatabase:PROD(DBID=39525561)

3.ShowingtheDefaultRMANConfiguration（RMAN的默认配置）
RMAN预先做了一些配置。showall可以显示配置
RMAN>showall;

4.BackingUpaDatabase（备份数据库）
用backup命令备份数据库，如果不手动指定设备和保存位置，会用配置好的设备来备份和保存备份文件。备份文件默认放在磁盘上的fastrecoveryarea.如果指定了format,则保存到format的位置,并且会自动给备份文件命名.
默认情况下,生成的文件是备份集,而不是copy(镜像).备份集一个或多个备份片(pieces),备份片只能由RMAN读定,其它程序无法访问.备份集包括了所有使用过的块(不包括未使用的块),备份集可以保存磁盘或磁带上
backupascopy备份生生成一个镜像,镜像是数据文件的复制,相当于操作系统的cp命令.注意:用操作系统cp命令复制数据文件是无效的,因为文件中的数据块是不一致的,用RMAN进行镜像备份是有效的,因为RMAN可以读取镜像和归档来保证数据块的一致性.

5.BackingUpaDatabaseinARCHIVELOGMode备份归档数据库
数据库运行在归档模式下,可以在数据库打开时备份(在线备份),如果运行在非归档模式下,只能在关闭后备份或才用EXPEXPDP进行逻辑备份.在线的备份称为不一致的备份,在进行恢复时需要使用日志文件来保证数据文件的一致性.可以把归档日志也备份下来:

RMAN>BACKUPDATABASEPLUSARCHIVELOG;

6.BackingUpaDatabaseinNOARCHIVELOGMode备份非归档的数据
在非归档下备份数据库,数据库必须先一致的关闭(shutdownnormalshutdowntransactionshutdonwimmediate),然后再启动到mount,再用RMAN备份,只有这样样,备份集才是一致的有效的.
过程如下:

RMAN>SHUTDOWNIMMEDIATE;
RMAN>STARTUPFORCEDBA;
RMAN>SHUTDOWNIMMEDIATE;
RMAN>STARTUPMOUNT;
RMAN>BACKUPDATABASE;或者RMAN>BACKUPASCOPYDATABASE;
RMAN>ALTERDATABASEOPEN;

7.TypicalBackupOptions典型的备份操作
RMAN支持多种备份选项,如:

Option	Description	Example
FORMAT	Specifiesalocationandnameforbackuppiecesandcopies.Youmustusesubstitutionvariablestogenerateuniquefilenames. Themostcommonsubstitutionvariableis %U ,whichgeneratesauniquename.Othersinclude %d fortheDB_NAME, %t forthebackupsettimestamp, %s forthebackupsetnumber,and %p forthebackuppiecenumber. 指定备份集搁置和名称格式.默认的名称格式是%U.%d表示DB_NAME,%t表示备份时的时间戳,%s设置备份集序号,p%设置备份片序号	BACKUP FORMAT'AL_%d/%t/%s/%p' ARCHIVELOGLIKE'%arc_dest%';
TAG	Specifiesauser-definedstringasalabelforthebackup.Ifyoudonotspecifyatag,thenRMANassignsadefaulttagwiththedateandtime.TagsarealwaysstoredintheRMANrepositoryinuppercase. 为本次备份设置一个别名,以便恢复时使用	BACKUP TAG'weekly_full_db_bkup' DATABASEMAXSETSIZE10M;

8.MakingIncrementalBackups增量备份
增量备份是指在上一次完全备份的基础上只备份修改过的块,通常比完全备份要块.如果没有完全备份,首次执行增量备份会进行完全备份作为0级增量备份.
增量备份分为两种:差异增量备份和累积增量备份.区别是,差异增量备份会备份同级别或以下级别备份以来修改的块,而累积备份只备份自身级别以下级别的备份.在执行恢复时,RMAN以上次的0级别和完全备份为起点来执行恢复.
执行增量备份:

BACKUPINCREMENTALLEVEL0DATABASE;
BACKUPINCREMENTALLEVEL1CUMULATIVEDATABASE;
BACKUPINCREMENTALLEVEL1DATABASE;

9.MakingIncrementallyUpdatedBackups增量更新备份
增量更新备份:以镜像备份为基础,将修改过的块合并到原来的镜像里做为一个新的镜像使用.过程如下
1.首先执行镜像备份,指定一个tag
2.执行1级的增量备份,指定上镜像同样的tag.BACKUPFORRECOVEROFCOPY只备份上次镜像以来修改的块.
增量更新备份包含了镜像备份以来修改的块,所以恢复的时候用的更快.
增量更新备份选项:

BACKUPOption	Description	Example
FORRECOVEROFCOPYWITHTAG ' tag_name '	Use TAG toidentifythetagofthedatafilecopyservingasbasisforthebackupstrategy.RMANautomaticallyassignsthesametagtoeverylevel1backupofthiscopy. Ifnolevel0datafilecopywiththespecifiedtagexistsineitherthecurrentorparentdatabaseincarnation,thenRMANcreatesalevel0datafilecopywiththespecifiedtag. 指定tag,然后RMAN会自动合并镜像.如果没有执行过镜像备份,则RMAN创建镜像备份	BACKUP INCREMENTALLEVEL1 FORRECOVEROFCOPY WITHTAG'incr_update' DATABASE;
FORRECOVEROFCOPYDATAFILECOPYFORMAT' format '	SpecifieswhereRMANcreatesthedatafilecopyifacopydoesnotexist.Ifyouaddanewdatafiletothedatabase,thenyoudonotneedtochangeyourscript,becauseRMANautomaticallycreatesthelevel0copyrequiredbytheincrementalbackuproutine. 备份数据文件镜像.	BACKUP INCREMENTALLEVEL1 FORRECOVEROFCOPY DATAFILECOPYFORMAT '/disk2/df1.cpy' DATABASE;

如:

RECOVERCOPYOFDATABASE
WITHTAG'incr_update';
BACKUP
INCREMENTALLEVEL1
FORRECOVEROFCOPYWITHTAG'incr_update'
DATABASE;

10.ValidatingDatabaseFilesandBackups验证数据文件和备份
用

VALIDATE

验证数据文件是否存在,是否有错误.CHECKLOGICAL命令验证数据文件是否有逻辑错误.
物理验证和逻辑验证数据文件和归档日志:

BACKUPVALIDATECHECKLOGICAL
DATABASEARCHIVELOGALL;

验证数据块:

VALIDATEDATAFILE4BLOCK10TO13;

验证备份集:

VALIDATEBACKUPSET3;

11.ScriptingRMANOperationsRMAN脚本
可以把RMAN命令保存在文本中执行.如:

#my_command_file.txt
CONNECTTARGET/
BACKUPDATABASEPLUSARCHIVELOG;
LISTBACKUP;
EXIT;

调用

%rman
RMAN>@/my_dir/my_command_file.txt#runsspecifiedcommandfile
或者
%rman@/my_dir/my_command_file.txt

12.ReportingonRMANOperationsRMAN报告
list和report命令可以显示备份相关信息,showall显示RMAN配置
1)list命令
listbackup和listcopy

listbackup:

Option	Example	Explanation
BY BACKUP	LIST BACKUP OF DATABASE BY BACKUP	Organizestheoutputbybackupset.Thisisthedefaultmodeofpresentation.
BY FILE	LIST BACKUP BY FILE	Liststhebackupsaccordingtowhichfilewasbackedup.
SUMMARY	LIST BACKUP SUMMARY	Displayssummaryoutput.

其它list选项:

Option	Example	Explanation
EXPIRED	LIST EXPIRED COPY 显示存在不RMAN资源库但不在磁盘上的备份	ListsbackupsthatarerecordedintheRMANrepositorybutthatwerenotpresentattheexpectedlocationondiskortapeduringthelast CROSSCHECK command.Anexpiredbackupmayhavebeendeletedbyanoperatingsystemutility.
RECOVERABLE	LIST BACKUPRECOVERABLE 显示可用的备份或镜像	Listsdatafilebackupsorcopiesthathavestatus AVAILABLE intheRMANrepositoryandthatcanberestoredandrecovered.

如:

LISTBACKUPOFDATABASE;
LISTCOPYOFDATAFILE1,2;
LISTBACKUPOFARCHIVELOGFROMSEQUENCE10;
LISTBACKUPSETOFDATAFILE1;

2)report
report选项:

Option	Example	Explanation
NEED BACKUP	REPORT NEED BACKUPDATABASE 在当前的保留策略下需要备份的文件	Showswhichfilesneedbackingupundercurrentretentionpolicy.Useoptional REDUNDANCY and RECOVERY WINDOW parameterstospecifydifferentcriteria.
OBSOLETE	REPORT OBSOLETE 报告过期的备份	Listsbackupsthatareobsoleteundertheconfiguredbackupretentionpolicy.Usetheoptional REDUNDANCY and RECOVERY WINDOW parameterstooverridethedefault.
SCHEMA	REPORT SCHEMA 显示表空间和数据文件	Reportsthetablespacesanddatafilesinthedatabaseatthecurrenttime(default)oradifferenttime.
UNRECOVERABLE	REPORT UNRECOVERABLE 显示无法恢复的数据文件	Listsalldatafilesforwhichanunrecoverableoperationhasbeenperformedagainstanobjectinthedatafilesincethelastbackupofthedatafile.

12.MaintainingRMANBackups维护RMAN备份
用来维护RMAN资源库的命令包括:

CATALOG

,

CHANGE

,

CROSSCHECK

,

DELETE

.
1)Cross-checkingBackups用crosscheck来检测备份
crosscheck用来检查备份集或状态是否有效并同步到控制文件.应该在删除备份集或镜像前做crosschek.备份在磁盘时,crosscheck检查文件头是否有效,有磁带时,会查询资源库.
检测备份和镜像:

CROSSCHECKBACKUP;
CROSSCHECKCOPY;

2)DeletingObsoleteBackups删除过期备份

delete命令用来从磁盘和磁带删除过期的备份和镜像,并修改控制文件和catalog里的备份信息.在交互式下,delete会先显示需要删除的文件,在用户确认后删除.如:

RMAN>deleteobsolete;

RMAN保留策略将应用于该命令
将RMAN保留策略设置为冗余1
分配的通道:ORA_DISK_1
通道ORA_DISK_1:SID=139设备类型=DISK
删除以下已废弃的备份和副本:
类型关键字完成时间文件名/句柄
----------------------------------------------------------------
存档日志512-5月-14D:\APP\WJ\PRODUCT\11.1.0\DB_1\RDBMS\ARC00059_0817241642.001
存档日志712-5月-14D:\APP\WJ\PRODUCT\11.1.0\DB_1\RDBMS\ARC00060_0817241642.001
存档日志912-5月-14D:\APP\WJ\PRODUCT\11.1.0\DB_1\RDBMS\ARC00061_0817241642.001
存档日志1112-6月-14D:\APP\WJ\FLASH_RECOVERY_AREA\ARC00075_0817241642.001
存档日志1213-6月-14D:\APP\WJ\FLASH_RECOVERY_AREA\ARC00076_0817241642.001
存档日志1313-6月-14D:\APP\WJ\FLASH_RECOVERY_AREA\ARC00077_0817241642.001
存档日志1420-6月-14D:\APP\WJ\FLASH_RECOVERY_AREA\ARC00078_0817241642.001
存档日志1523-6月-14D:\APP\WJ\FLASH_RECOVERY_AREA\ARC00079_0817241642.001

是否确定要删除以上对象(输入YES或NO)?no

13.DiagnosingandRepairingFailureswithDataRecoveryAdvisor数据恢复顾问
DRA可以检测永久性的错误,提供修复建议或者自动执行修复.
failure指被HealthMonitor检测出的数据块错误.每个错误有错误优先级和错误状态.如

CRITICAL

,

HIGH

,or

LOW

和

OPEN

or

CLOSED.

listfailure会显示错误,advisorfailure提供错误修改建议,reparitfailure尝试修改错误.
如:

RMAN>LISTFAILURE;

ListofDatabaseFailures
=========================

FailureIDPriorityStatusTimeDetectedSummary
-----------------------------------------------
142HIGHOPEN23-APR-07Oneormorenon-systemdatafilesaremissing
101HIGHOPEN23-APR-07Datafile1:'/disk1/oradata/prod/system01.dbf'
containsoneormorecorruptblocks

RMAN>
ADVISEFAILURE;

ListofDatabaseFailures
=========================

FailureIDPriorityStatusTimeDetectedSummary
-----------------------------------------------
142HIGHOPEN23-APR-07Oneormorenon-systemdatafilesaremissing
101HIGHOPEN23-APR-07Datafile1:'/disk1/oradata/prod/system01.dbf'
containsoneormorecorruptblocks

analyzingautomaticrepairoptions;thismaytakesometime
usingchannelORA_DISK_1
analyzingautomaticrepairoptionscomplete

MandatoryManualActions
========================
nomanualactionsavailable

OptionalManualActions
=======================
1.Iffile/disk1/oradata/prod/users01.dbfwasunintentionallyrenamedormoved,restoreit

AutomatedRepairOptions
========================
OptionRepairDescription
------------------------
1Restoreandrecoverdatafile28;Performblockmediarecoveryof
block56416infile1
Strategy:Therepairincludescompletemediarecoverywithnodataloss
Repairscript:/disk1/oracle/log/diag/rdbms/prod/prod/hm/reco_660500184.hm

首先尝试人工修复(在某些情况下人工修复比自动修复要快,如控制文件丢失),在人工修复不能完成的情况下使用自动修复
repair尝试修复错误,会将出现的错误一起修复.

RMAN>REPAIRFAILURE;

在执行修复前,会进行提示,确认后才会执行.在修复完成后,DRA会把已经修复的错误从当前的错误列表删除.

14.RewindingaDatabasewithFlashbackDatabase
用flashback将数据库闪回到某个点,不像介质恢复,不需要还原数据文件,速度很快.
在使用flashbackdatabase前,必须开启闪回日志(flashbacklog).闪回操作使用闪回日志把数据块的更新还原,不能用闪回来做介质恢复和数据文件丢失.
数据库必须在mount下进行闪回,
如下在RMAN中使用闪回:

SHUTDOWNIMMEDIATE;
STARTUPMOUNT;
FLASHBACKDATABASETOSCN861150;

FLASHBACKDATABASE
TORESTOREPOINTBEFORE_CHANGES;

FLASHBACKDATABASE
TOTIMESTAMPTO_DATE(04-DEC-200903:30:00','DD-MON-YYYYHH24:MI:SS');

SQL"ALTERDATABASEOPENREADONLY";

SHUTDOWNIMMEDIATE;
STARTUPMOUNT;
ALTERDATABASEOPENRESETLOGS;

15.RestoringandRecoveringDatabaseFiles
1)还原和恢复数据库前需要做的准备.显示可以还原的最小SCN
RESTORE...PREVIEW文件命令用来显示可以进行恢复的最小SCN号,在执行这个命令时,RMAN只是读元数据并且备份的文件.

RMAN>RESTOREDATABASEPREVIEWSUMMARY;

Startingrestoreat21-MAY-07
allocatedchannel:ORA_DISK_1
channelORA_DISK_1:SID=80devicetype=DISK

ListofBackups
===============
KeyTYLVSDeviceTypeCompletionTime#Pieces#CopiesCompressedTag
-----------------------------------------------------------------
11BFADISK18-MAY-0712NOTAG20070518T181114
13BFADISK18-MAY-0712NOTAG20070518T181114
usingchannelORA_DISK_1

ListofArchivedLogCopiesfordatabasewithdb_unique_namePROD
=====================================================================

KeyThrdSeqSLowTime
----------------------------
47118A18-MAY-07
Name:/disk1/oracle/dbs/db1r_60ffa882_1_18_0622902157.arc

MediarecoverystartSCNis586534
RecoverymustbedonebeyondSCN587194tocleardatafilefuzziness
validationsucceededforbackuppiece
Finishedrestoreat21-MAY-07

2)RecoveringtheWholeDatabase恢复整个数据库
使用restoredatabase和recoverdatabase来还原和恢复数据.前提是必须要有可用的数据库备份.如果不想把文件还原在原来的位置,使用setnewname命令来指定新的位置

启动数据库到mount,如果无法启动到mount,执行
RMAN>STARTUPFORCEMOUNT;
RMAN>RESTOREDATABASE;
RMAN>RECOVERDATABASE;
RMAN>ALTERDATABASEOPEN;

3)RecoveringTablespaces恢复表空间

RESTORE

TABLESPACE

和

RECOVER

TABLESPACE

用来还原和恢复单个表空间,可以在数据库打开的情况下执行.首先,要把表空间脱机,然后执行restore再执行recover,再把表空间联机online
如果需要把数据文件还原到新的位置,设置setnewname,然后执行SWITCHDATAFILEALL,情相当于ALTERDATABASERENAMEFILE命令来更新控制文件信息.
注意:在执行表空间恢复时,不能将表空间设置为备份模式.

RMAN>SQL'ALTERTABLESPACEusersOFFLINE';
RUN
{
SETNEWNAMEFORDATAFILE'/disk1/oradata/prod/users01.dbf'
TO'/disk2/users01.dbf';
RESTORETABLESPACEusers;
SWITCHDATAFILEALL;#updatecontrolfilewithnewfilenames
RECOVERTABLESPACEusers;
}
RMAN>SQL'ALTERTABLESPACEusersONLINE';

3)RecoveringIndividualDataBlocks
用RMAN执行数据文件或备份后验证后,错误的数据块会记录在V$DATABASE_BLOCK_CORRUPTION中,错误信息会记录在alert,trace文件中.

RMAN>RECOVERCORRUPTIONLIST;--修复所有错误块
RMAN>RECOVERDATAFILE1BLOCK233,235DATAFILE2BLOCK100TO200;修复指定的错误块

来自为知笔记(Wiz)