RMAN备份详解

 

1.7.1数据库备份与RMAN备份的概念

   

    1.数据库完全备份:按归档模式分为归档和非归档

        归档模式

            打开状态,属于非一致性备份

            关闭状态,可以分为一致性和非一致性

        非归档模式

            打开状态,非一致性备份无效

            关闭状态,一致性备份,非一致性备份不被推荐

    2.RMAN备份     

        RMAN使用服务器会话来完成备份操作,从RMAN客户端连接到服务器将产生一个服务器会话

        RMAN备份内容包括:整个数据库,表空间,数据文件,指定的数据文件,控制文件,归档日志文件,参数文件等

       

    3.RMAN备份的类型

        完整备份(full) 或增量备份(incremental)

        一致性备份(consistent)或不一致性备份(inconsistent)

        热备(open)或冷备(closed),冷备时数据库必须处于mount状态,冷备可以为一致性备份或非一致性备份

               

        完整备份

            一个或多个数据文件的一个完整副本,包含从备份开始处所有的数据块.完整备份不能作为增量的基础

           

        增量备份

            包含从最近一次备份以来被修改或添加的数据块.可以分为差异增量备份和累计增量备份

            差异增量备份仅仅包含n级或n级以下被修改过的数据块。备份数据量小,恢复时间长。

            累计增量备份仅仅包含n-1级或n-1级以下被修改过的数据块。备份数据量大,恢复时间短。

            0级增量备份相当于一个完整备份,该备份包含所有已用的数据块文件,与完整备份的差异是完整备份不能用作级增量备份的基础

                       

        一致性备份

            备份所包含的各个文件中的所有修改都具备相同的系统变化编号(system change number,SCN)。

            也就是说,备份所包含的各个文件中的所有数据均来自同一时间点。

            一致性数据库完全备份(consis-tent whole database backup)进行还原(restore)后,不需要执行恢复操作(recovery)

       

        非一致性备份

            在数据库处于打开(open)状态时,或数据库异常关闭(shut down abnormally)后,对一个或多个数据

            库文件进行的备份。非一致性备份需要在还原之后进行恢复操作

   

    4.备份集与镜像副本

        备份集

            是包含一个或多个数据文件,归档日志文件的二进制文件的集合.备份集由备份片组成,一个备份集中可以包含一个或多个备份片

            可以通过filesperset参数来设置备份集中可包含的备份片数,

            也可以设定参数maxpiecesize来制定每个备份片的大小。

            备份集中空闲的数据块将不会被备份,因此备份集可以支持压缩。备份集支持增量备份,可以备份到磁盘或磁带。

           

        镜像副本

            是数据文件或归档日志文件等的完整拷贝,未经过任何压缩等处理,不能备份到磁带,也不支持增量备份

            恢复时可以立即使用实现快速恢复

            等同于操作系统的复制命令

            可以作为级增量备份

   

    5.备份路径

        可以备份到磁盘目录

        可以备份到磁带

        闪回区

   

    6.备份限制

        数据库必须处于mount或open状态

        不能备份联机日志

        在非归档模式下仅仅能作干净备份,即在干净关闭且启动到mount状态下备份

        在归档模式下,current状态下数据文件可以备份

       

     关于更多备份与恢复的概念请参考:Oracle 备份恢复概念

       

1.7.2使用RMAN进行备份

    1.7.2.1备份数据库

        RMAN> show all;

        RMAN configuration parameters are:

        CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default

        CONFIGURE BACKUP OPTIMIZATION OFF; # default

        CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default

        CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default

        CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default

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

        CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default

        CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default

        CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT   '/u01/app/oracle/rmanbak/df_%d_%U';

        CONFIGURE MAXSETSIZE TO UNLIMITED; # default

        CONFIGURE ENCRYPTION FOR DATABASE OFF; # default

        CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default

        CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default

        CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/10g/dbs/snapcf_orcl.f'; # defaul       

 

        RMAN> backup database format '/u01/app/oracle/rmanbak/whole_%d_%U';  --备份整个数据库

        RMAN> backup as compressed backupset database format '/u01/app/oracle/rmanbak/whole_%d_%U';--备份整个数据库并压缩备份集

 rman>backup database plus archivelog;

rman>backup database plus archivelogdelete all input;

rman>backup as compressed backupset database include current controlfile plus archivelog delete all input;

        RMAN> run{

        allocate channel ch1 type disk                      --手动分配一个通道

        maxpiecesize=2g;                              --指定备份片的大小为2g

        backup as compressed backupset                      --压缩备份集

        format  '/u01/app/oracle/rmanbak/whole_%d_%U' filesperset=3--指定备份集中允许容纳的文件数为个

         database;

        release channel ch1;}                           --释放通道

 

        RMAN> configure device type disk parallelism 3;   --将并行度改为

 

        old RMAN configuration parameters:

        CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET;

        new RMAN configuration parameters:

        CONFIGURE DEVICE TYPE DISK PARALLELISM 3 BACKUP TYPE TO BACKUPSET;

        new RMAN configuration parameters are successfully stored

 

        RMAN> backup as compressed backupset    --并行度改为之后,自动启用了个通道

        2> format '/u01/app/oracle/rmanbak/whole_%d_%U' filesperset=3

        3> database;

 

        Starting backup at 14-OCT-10

        allocated channel: ORA_DISK_1

        channel ORA_DISK_1: sid=148 devtype=DISK    --sid值对应v$session视图中的sid

        allocated channel: ORA_DISK_2

        channel ORA_DISK_2: sid=146 devtype=DISK

        allocated channel: ORA_DISK_3

        channel ORA_DISK_3: sid=144 devtype=DISK

 

        RMAN> run{

        2> allocate channel ch1 type disk

        3> maxpiecesize=100m;   --备份片大小设置为m,则一个备份集包含多个备份片,且每个备份片大小为100m

        4> backup

        5> format '/u01/app/oracle/rmanbak/whole_%d_%U'

        6> database;

        7> release channel ch1;}

 

        RMAN> list backupset tag=TAG20101014T171115;

 

        List of Backup Sets

        ===================

 

        BS Key  Type LV Size       Device Type Elapsed Time Completion Time

        ------- ---- -- ---------- ----------- ------------ ---------------

        21      Full    690.30M    DISK        00:01:39     14-OCT-10

          List of Datafiles in backup set 21

          File LV Type Ckp SCN    Ckp Time   Name

          ---- -- ---- ---------- ---------- ----

          1       Full 1648791    14-OCT-10 /u01/app/oracle/oradata/orcl/system01.dbf

          2       Full 1648791    14-OCT-10 /u01/app/oracle/oradata/orcl/undotbs01.dbf

          3       Full 1648791    14-OCT-10 /u01/app/oracle/oradata/orcl/sysaux01.dbf

          4       Full 1648791    14-OCT-10 /u01/app/oracle/oradata/orcl/users01.dbf

          5       Full 1648791    14-OCT-10 /u01/app/oracle/oradata/orcl/example01.dbf

          6       Full 1648791    14-OCT-10 /u01/app/oracle/oradata/orcl/tbs1.dbf

 

          Backup Set Copy #1 of backup set 21

          Device Type Elapsed Time Completion Time Compressed Tag

          ----------- ------------ --------------- ---------- ---

          DISK        00:01:39     14-OCT-10      NO         TAG20101014T171115

 

            List of Backup Pieces for backup set 21 Copy #1

            BP Key  Pc# Status      Piece Name

            ------- --- ----------- ----------

            21      1   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_1_1

            22      2   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_2_1

            23      3   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_3_1

            24      4   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_4_1

            25      5   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_5_1

            26      6   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_6_1

            27      7   AVAILABLE   /u01/app/oracle/rmanbak/whole_ORCL_0nlqemtj_7_1

 

        BS Key  Type LV Size       Device Type Elapsed Time Completion Time

        ------- ---- -- ---------- ----------- ------------ ---------------

        22      Full    6.80M      DISK        00:00:01     14-OCT-10

                BP Key: 28   Status: AVAILABLE  Compressed: NO  Tag: TAG20101014T171115

                Piece Name: /u01/app/oracle/rmanbak/whole_ORCL_0olqen0s_1_1

          Control File Included: Ckp SCN: 1648817      Ckp time: 14-OCT-10

          SPFILE Included: Modification time: 14-OCT-10

 

    -----------------------------------------------------------------------------------------------------------------------

    1.7.2.2备份数据文件

        Oracle数据文件及表空间的管理请参考:Oracle 表空间与数据文件

        RMAN> backup as copy datafile 4                                             --备份类型为镜像备份

        2> format '/u01/app/oracle/rmanbak/df_%d_%U';

 

        RMAN> list copy; 

 

        RMAN> backup datafile 4,5,6 format '/u01/app/oracle/rmanbak/df_%d_%U';      --备份类型为备份集

 

    -----------------------------------------------------------------------------------------------------------------------

    1.7.7.3备份表空间

        Oracle数据文件及表空间的管理请参考:Oracle 表空间与数据文件

 

        RMAN>  backup tablespace users,example format '/u01/app/oracle/rmanbak/tb_%d_%U';

 

        RMAN> backup tablespace temp;  --临时表空间不需要备份

 

        Starting backup at 14-OCT-10

        using channel ORA_DISK_1

        using channel ORA_DISK_2

        RMAN-00571: ===========================================================

        RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

        RMAN-00571: ===========================================================

        RMAN-03002: failure of backup command at 10/14/2010 18:56:12

        RMAN-20202: tablespace not found in the recovery catalog

        RMAN-06019: could not translate tablespace name "TEMP"

 

    -----------------------------------------------------------------------------------------------------------------------

    1.7.7.4备份控制文件

        Oracle 控制文件的详细介绍请参考:Oracle 控制文件(CONTROLFILE)

 

        RMAN> configure controlfile autobackup on;--自动备份控制文件置为on状态,将自动备份控制文件和参数文件

 

        old RMAN configuration parameters:

        CONFIGURE CONTROLFILE AUTOBACKUP OFF;

        new RMAN configuration parameters:

        CONFIGURE CONTROLFILE AUTOBACKUP ON;

        new RMAN configuration parameters are successfully stored

 

        注:在备份system01.dbf或system表空间时将会自动备份控制文件和参数文件,即使自动备份控制文件参数为off

 

        --单独备份控制文件及参数文件

        RMAN> backup current controlfile;

 

        --备份数据文件时包含控制文件

        RMAN> backup datafile 4 include current controlfile;

 

        RMAN> sql "alter database backup controlfile to ''/tmp/orclcontrol.bak''";

 

        sql statement: alter database backup controlfile to ''/tmp/orclcontrol.bak''

 

        RMAN>  sql "alter database backup controlfile to trace as ''/tmp/orclcontrol.sql''";

 

        sql statement: alter database backup controlfile to trace as ''/tmp/orclcontrol.sql''

 

        --单独备份spfile

        RMAN> backup spfile format '/u01/app/oracle/rmanbak/sp_%d_%U';

 

        RMAN> backup copies 2 device type disk spfile;

 

    -----------------------------------------------------------------------------------------------------------------------

    1.7.7.5备份归档日志文件

        备份归档日志时仅仅备份归档过的数据文件(不备份联机重做日志文件)

        备份归档日志时总是对归档日志做完整备份

        RMAN对归档日志备份前会自动做一次日志切换,且从一组归档日志中备份未损坏的归档日志

        RMAN会自动判断哪些归档日志需要进行备份

        归档日志的备份集不能包含其它类型的文件

 

        关于Oracle日志文件请参考:Oracle 联机重做日志文件(ONLINE LOG FILE)

        关于Oracle归档日志请参考:Oracle 归档日志

 

        RMAN> backup

        2> format '/u01/app/oracle/rmanbak/lf_%d_%U'

        3> archivelog all delete input;   --delete input 删除所有已经备份过的归档日志

 

        RMAN> backup            --此种写法实现了上述相同的功能

        2> archivelog all delete input

        3> format '/u01/app/oracle/rmanbak/lf_%d_%U';

 

        RMAN>backup archivelog sequence between 50 and 120 thread 1 delete input;

 

        RMAN> backup archivelog from time "sysdate-15" until time "sysdate-7";

       

        RMAN> backup

        2> format '/u01/app/oracle/rmanbak/lf_%d_%U'

        3> archivelog from sequence=80

        4> delete input;

 

        使用plus archivelog时备份数据库完成的动作(backup database plus archivelog)

            1.首先执行alter system archive log current 命令(对当前日志归档)

            2.执行backup archivelog all 命令(对所有归档日志进行备份)

            3.执行backup database命令中指定的数据文件、表空间等

            4.再次执行alter system archive log current

            5.备份在备份操作期间产生的新的归档日志

 

        --执行下面的命令,并观察备份列出的信息,可以看到使用plus archivelog时使用了上面描述的步骤来进行备份

        RMAN> backup database plus archivelog

        2> format  '/u01/app/oracle/rmanbak/lg_%d_%U' delete input;

 

    1.7.7.6备份闪回区

       

        RMAN> backup recovery area;

            使用backup recovery area时,将备份位于闪回区且未进行过备份的所有文件,这些文件包括完整、增量备份集、自动备份的

            控制文件(假定使用闪回区作为备份路径时)、归档日志、数据文件的镜像副本等。闪回日志,当前的控制文件。

            联机重做日志不会被备份

       

        RMAN> backup recovery files;

            使用backup recovery files时,将备份磁盘上未进行过备份的所有恢复文件,而不论是否位于闪回区

           

        注:使用上述两条命令时,备份目的地必须是磁带

       

    7.总结:

        数据文件的备份集对于未使用的块可以执行增量备份,可以跳过未使用过的数据块来进行压缩备份

        对于控制文件、归档日志文件、spfile文件则是简单的拷贝,并对其进行打包压缩而已

 

posted @ 2015-01-11 17:12  智能先行者  阅读(515)  评论(0编辑  收藏  举报