第八章： Rman备份
1、rman备份分类：
1）归档：可以做一致性和非一致性备份
2）非归档：一致性备份
2、rman备份的分类：
1）backupset
-------一致性备份
RMAN> run {
2> shutdown immediate;
3> startup mount;
4> allocate channel c1 type disk;
5> allocate channel c2 type disk;
6> backup database format '/disk1/rman/prod/%d_%s.bak';
7> alter database open;
8> }
---------非一致性备份
RMAN> backup database format='/disk1/rman/prod/prod_%s.bak' filesperset 3;
RMAN> backup tablespace users format '/disk1/rman/prod/users_%s.bak' tag=userbak;
RMAN> backup datafile 2,3,5 format '/disk1/rman/prod/%d_%s.bak';
2）snapshot 镜像
RMAN> copy datafile 2 to '/disk1/rman/prod/users_%s.bak';
RMAN> backup as copy tablespace users format='/disk1/rman/prod/%d_users_%s.bak'；
[oracle@work ~]$ ls -lth /disk1/rman/prod
total 101M
-rw-r----- 1 oracle oinstall 101M Aug 18 06:12 users_15.bak
[oracle@work ~]$
-------生成的备份文件的大小和原datafile大小相同
3、增量备份：只备份发生变化的block（rman通过在备份时记录datablock的scn，下次备份时通过比较上次备份的数据块上的scn来确定数据块是否发生变化）
1）差异增量备份（Differential incremental backup）：下次备份时比较上次以来同级别或低级别的备份，为备份基础
-----0级备份
RMAN> backup incremental level 0 format '/disk1/rman/prod/users_0_%s.bak' tablespace users;
RMAN> list backup;
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
16 Incr 0 464.00K DISK 00:00:01 18-AUG-11
BP Key: 16 Status: AVAILABLE Compressed: NO Tag: TAG20110818T064000
Piece Name: /disk1/rman/prod/users_0_19.bak
List of Datafiles in backup set 16
File LV Type Ckp SCN Ckp Time Name
---- -- ---- ---------- --------- ----
2 0 Incr 1319567 18-AUG-11 /u01/app/oracle/oradata/prod/users01.dbf
------2级备份
RMAN> backup incremental level 2 format '/disk1/rman/prod/users_2_%s.bak' tablespace users;
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
18 Incr 2 112.00K DISK 00:00:01 18-AUG-11
BP Key: 18 Status: AVAILABLE Compressed: NO Tag: TAG20110818T064135
Piece Name: /disk1/rman/prod/users_2_21.bak
List of Datafiles in backup set 18
File LV Type Ckp SCN Ckp Time Name
---- -- ---- ---------- --------- ----
2 2 Incr 1319644 18-AUG-11 /u01/app/oracle/oradata/prod/users01.dbf
------1级备份
RMAN> backup incremental level 1 format '/disk1/rman/prod/users_1_%s.bak' tablespace users;
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
22 Incr 1 176.00K DISK 00:00:01 18-AUG-11
BP Key: 22 Status: AVAILABLE Compressed: NO Tag: TAG20110818T064323
Piece Name: /disk1/rman/prod/users_1_25.bak
List of Datafiles in backup set 22
File LV Type Ckp SCN Ckp Time Name
---- -- ---- ---------- --------- ----
2 1 Incr 1319760 18-AUG-11 /u01/app/oracle/oradata/prod/users01.dbf
2）累积增量备份的区别：只比较比自己级别低的作为备份基础
-------2级备份
RMAN> backup incremental level 2 cumulative format '/disk1/rman/prod/users_2cu_%s.bak' tablespace users;
-----1级备份
RMAN> backup incremental level 1 cumulative format '/disk1/rman/prod/users_1cu_%s.bak' tablespace users;
4、自动备份controlfile 和 spfile