RMAN（2）--- 基本配置

1. RMAN的默认配置

RMAN> show all;

using target database control file instead of recovery catalog
RMAN configuration parameters for database with db_unique_name OCP12C are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON; # 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 MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default
CONFIGURE RMAN OUTPUT TO KEEP FOR 7 DAYS; # default    ---- 所有的操作和结果都保存在 v$rman_output视图中，且保留七天
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/product/12.2.0.1/db_1/dbs/snapcf_OCP12C.f'; # default

RMAN>

 2.  含义

　　1. 保留策略

　　　　RMAN> CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default --- 冗余策略，规定至少有几个冗余的备份（默认为1），RMAN会从最新的备份开始保留N个数据备份，其他的会被打标成obsolete（废弃）对于同一个文件，如果备份了两次，则第一次的备份文件会被打标成废弃，RMAN只会寻找最新的备份文件进行恢复，在report obsolete 时，会看到第一次的备份文件，如果把最新的备份文件删除，则rman会寻找第一次备份的文件，此时report obsolete是看不到任何文件的

冗余策略为1，第一次备份15号数据文件
RMAN> backup datafile 15 format '/u01/app/oracle/backup/%U.15bak';

Starting backup at 2021-01-21 16:39:30
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00015 name=/u01/app/oracle/oradata/OCP12C/ERP/test01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 16:39:30
channel ORA_DISK_1: finished piece 1 at 2021-01-21 16:39:31
piece handle=/u01/app/oracle/backup/0jvl6ti2_1_1.15bak tag=TAG20210121T163930 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2021-01-21 16:39:31

Starting Control File and SPFILE Autobackup at 2021-01-21 16:39:31
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-02 comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 16:39:35

RMAN> list backup;


List of Backup Sets
===================


BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
17      Full    1.04M      DISK        00:00:00     2021-01-21 16:39:30
        BP Key: 17   Status: AVAILABLE  Compressed: NO  Tag: TAG20210121T163930
        Piece Name: /u01/app/oracle/backup/0jvl6ti2_1_1.15bak
  List of Datafiles in backup set 17
  Container ID: 3, PDB Name: ERP
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  15      Full 5982209    2021-01-21 16:39:30              NO    /u01/app/oracle/oradata/OCP12C/ERP/test01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
18      Full    18.25M     DISK        00:00:02     2021-01-21 16:39:34
        BP Key: 18   Status: AVAILABLE  Compressed: NO  Tag: TAG20210121T163932
        Piece Name: /u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-02
  SPFILE Included: Modification time: 2021-01-21 11:00:59
  SPFILE db_unique_name: OCP12C
  Control File Included: Ckp SCN: 5982219      Ckp time: 2021-01-21 16:39:32

RMAN> report obsolete;

RMAN retention policy will be applied to the command
RMAN retention policy is set to redundancy 1
Report of obsolete backups and copies
Type                 Key    Completion Time    Filename/Handle
-------------------- ------ ------------------ --------------------
Control File Copy     1      2021-01-17 12:45:29 /u01/app/oracle/backup/cdb/bak.ctl ----之前废弃的文件

第二次备份15号文件
RMAN> backup datafile 15 format '/u01/app/oracle/backup/%U.15bak';

Starting backup at 2021-01-21 16:40:31
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00015 name=/u01/app/oracle/oradata/OCP12C/ERP/test01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 16:40:32
channel ORA_DISK_1: finished piece 1 at 2021-01-21 16:40:33
piece handle=/u01/app/oracle/backup/0lvl6tk0_1_1.15bak tag=TAG20210121T164031 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2021-01-21 16:40:33

Starting Control File and SPFILE Autobackup at 2021-01-21 16:40:33
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-03 comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 16:40:34

RMAN> report obsolete;

RMAN retention policy will be applied to the command
RMAN retention policy is set to redundancy 1
Report of obsolete backups and copies
Type                 Key    Completion Time    Filename/Handle
-------------------- ------ ------------------ --------------------
Control File Copy     1      2021-01-17 12:45:29 /u01/app/oracle/backup/cdb/bak.ctl
Backup Set           17     2021-01-21 16:39:30
  Backup Piece       17     2021-01-21 16:39:30 /u01/app/oracle/backup/0jvl6ti2_1_1.15bak ---将第一次备份的文件标记成了obsolete

　　　　RMAN> CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS; --- 时间窗口策略 ---- 使用这种保留策略意味着，在恢复窗口期的数据，任何地方出问题，RMAN都要通过保留策略保存的备份恢复出来。注意：恢复窗口是个时间段，和这个时间段有无备份，或有多少备份无关。窗口期内的任意一点被损坏，都要能保证备份文件被恢复，所以窗口期前的一份备份是不会被标记为 obsolete的

　　　　RMAN> CONFIGURE RETENTION POLICY TO NONE; ---- 将保留策略设置成NONE后，不会有任何一个备份被标记成obsolete。

　　注意：保留策略只能选择其中一个，不能同时设置多个

　　2. 备份优化

　　　　RMAN> CONFIGURE BACKUP OPTIMIZATION OFF; # default  --- 默认是关闭，如果开启了备份优化，可以避免重复备份，只用于归档日志，只读，或脱机表空间的数据文件，备份优化选项依赖于RETENTION POLICY策略，如果启用优化，在已有足够相同文件副本的情况下，采用（N+1），RMAN将不创建额外的文件副本。

先将其中一个表空间设置成只读模式
SQL> alter tablespace hehe read only;

Tablespace altered.

SQL> select tablespace_name, status from dba_tablespaces where tablespace_name='HEHE';

TABLESPACE_NAME                          STATUS
------------------------------------------------------------ ------------------
HEHE                                 READ ONLY

开启备份优化
RMAN> CONFIGURE BACKUP OPTIMIZATION on;

new RMAN configuration parameters:
CONFIGURE BACKUP OPTIMIZATION ON;
new RMAN configuration parameters are successfully stored

进行三次同样的备份，查看第二次和第三次的区别（冗余策略是1）
RMAN> backup database format '/u01/app/oracle/backup/%U.full';

Starting backup at 2021-01-21 17:21:58
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00003 name=/u01/app/oracle/oradata/OCP12C/sysaux01.dbf
input datafile file number=00001 name=/u01/app/oracle/oradata/OCP12C/system01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/OCP12C/undotbs01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/OCP12C/users01.dbf
input datafile file number=00016 name=/u01/app/oracle/oradata/OCP12C/hehe01.dbf
input datafile file number=00017 name=/u01/app/oracle/oradata/OCP12C/memeda01.dbf
input datafile file number=00019 name=/u01/app/oracle/oradata/OCP12C/xxp01.dbf
input datafile file number=00020 name=/u01/app/oracle/oradata/OCP12C/aaa01.dbf
input datafile file number=00023 name=/u01/app/oracle/backup/lalala01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:21:59


channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:27:34
piece handle=/u01/app/oracle/backup/0vvl701n_1_1.full tag=TAG20210121T172158 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:05:35
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00010 name=/u01/app/oracle/oradata/OCP12C/ERP/sysaux01.dbf
input datafile file number=00009 name=/u01/app/oracle/oradata/OCP12C/ERP/system01.dbf
input datafile file number=00011 name=/u01/app/oracle/oradata/OCP12C/ERP/undotbs01.dbf
input datafile file number=00012 name=/u01/app/oracle/oradata/OCP12C/ERP/users01.dbf
input datafile file number=00015 name=/u01/app/oracle/oradata/OCP12C/ERP/test01.dbf
input datafile file number=00018 name=/u01/app/oracle/oradata/OCP12C/ERP/xxp01.dbf
input datafile file number=00021 name=/u01/app/oracle/backup/aaa01.dbf
input datafile file number=00022 name=/u01/app/oracle/oradata/OCP12C/ERP/lalala01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:27:35
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:28:10
piece handle=/u01/app/oracle/backup/10vl70c6_1_1.full tag=TAG20210121T172158 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:35
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00006 name=/u01/app/oracle/oradata/OCP12C/pdbseed/sysaux01.dbf
input datafile file number=00005 name=/u01/app/oracle/oradata/OCP12C/pdbseed/system01.dbf
input datafile file number=00008 name=/u01/app/oracle/oradata/OCP12C/pdbseed/undotbs01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:28:10
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:28:36
piece handle=/u01/app/oracle/backup/11vl70da_1_1.full tag=TAG20210121T172158 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:26
Finished backup at 2021-01-21 17:28:36

Starting Control File and SPFILE Autobackup at 2021-01-21 17:28:36
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-07 comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 17:28:39

RMAN>
RMAN>
RMAN> backup database format '/u01/app/oracle/backup/%U.full';

Starting backup at 2021-01-21 17:29:58
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00003 name=/u01/app/oracle/oradata/OCP12C/sysaux01.dbf
input datafile file number=00001 name=/u01/app/oracle/oradata/OCP12C/system01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/OCP12C/undotbs01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/OCP12C/users01.dbf
input datafile file number=00016 name=/u01/app/oracle/oradata/OCP12C/hehe01.dbf
input datafile file number=00017 name=/u01/app/oracle/oradata/OCP12C/memeda01.dbf
input datafile file number=00019 name=/u01/app/oracle/oradata/OCP12C/xxp01.dbf
input datafile file number=00020 name=/u01/app/oracle/oradata/OCP12C/aaa01.dbf
input datafile file number=00023 name=/u01/app/oracle/backup/lalala01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:29:58
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:31:15
piece handle=/u01/app/oracle/backup/13vl70gm_1_1.full tag=TAG20210121T172958 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:17
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00010 name=/u01/app/oracle/oradata/OCP12C/ERP/sysaux01.dbf
input datafile file number=00009 name=/u01/app/oracle/oradata/OCP12C/ERP/system01.dbf
input datafile file number=00011 name=/u01/app/oracle/oradata/OCP12C/ERP/undotbs01.dbf
input datafile file number=00012 name=/u01/app/oracle/oradata/OCP12C/ERP/users01.dbf
input datafile file number=00015 name=/u01/app/oracle/oradata/OCP12C/ERP/test01.dbf
input datafile file number=00018 name=/u01/app/oracle/oradata/OCP12C/ERP/xxp01.dbf
input datafile file number=00021 name=/u01/app/oracle/backup/aaa01.dbf
input datafile file number=00022 name=/u01/app/oracle/oradata/OCP12C/ERP/lalala01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:31:16
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:31:51
piece handle=/u01/app/oracle/backup/14vl70j4_1_1.full tag=TAG20210121T172958 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:35
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00006 name=/u01/app/oracle/oradata/OCP12C/pdbseed/sysaux01.dbf
input datafile file number=00005 name=/u01/app/oracle/oradata/OCP12C/pdbseed/system01.dbf
input datafile file number=00008 name=/u01/app/oracle/oradata/OCP12C/pdbseed/undotbs01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:31:51
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:32:17
piece handle=/u01/app/oracle/backup/15vl70k7_1_1.full tag=TAG20210121T172958 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:26
Finished backup at 2021-01-21 17:32:17

Starting Control File and SPFILE Autobackup at 2021-01-21 17:32:17
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-08 comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 17:32:18

RMAN> backup database format '/u01/app/oracle/backup/%U.full';

Starting backup at 2021-01-21 17:33:22
using channel ORA_DISK_1
skipping datafile 5; already backed up 2 time(s)
skipping datafile 6; already backed up 2 time(s)
skipping datafile 8; already backed up 2 time(s)
skipping datafile 16; already backed up 2 time(s)
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00003 name=/u01/app/oracle/oradata/OCP12C/sysaux01.dbf
input datafile file number=00001 name=/u01/app/oracle/oradata/OCP12C/system01.dbf
input datafile file number=00004 name=/u01/app/oracle/oradata/OCP12C/undotbs01.dbf
input datafile file number=00007 name=/u01/app/oracle/oradata/OCP12C/users01.dbf
input datafile file number=00017 name=/u01/app/oracle/oradata/OCP12C/memeda01.dbf
input datafile file number=00019 name=/u01/app/oracle/oradata/OCP12C/xxp01.dbf
input datafile file number=00020 name=/u01/app/oracle/oradata/OCP12C/aaa01.dbf
input datafile file number=00023 name=/u01/app/oracle/backup/lalala01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:33:23
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:34:39
piece handle=/u01/app/oracle/backup/17vl70n3_1_1.full tag=TAG20210121T173323 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:16
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00010 name=/u01/app/oracle/oradata/OCP12C/ERP/sysaux01.dbf
input datafile file number=00009 name=/u01/app/oracle/oradata/OCP12C/ERP/system01.dbf
input datafile file number=00011 name=/u01/app/oracle/oradata/OCP12C/ERP/undotbs01.dbf
input datafile file number=00012 name=/u01/app/oracle/oradata/OCP12C/ERP/users01.dbf
input datafile file number=00015 name=/u01/app/oracle/oradata/OCP12C/ERP/test01.dbf
input datafile file number=00018 name=/u01/app/oracle/oradata/OCP12C/ERP/xxp01.dbf
input datafile file number=00021 name=/u01/app/oracle/backup/aaa01.dbf
input datafile file number=00022 name=/u01/app/oracle/oradata/OCP12C/ERP/lalala01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 17:34:39
channel ORA_DISK_1: finished piece 1 at 2021-01-21 17:35:04
piece handle=/u01/app/oracle/backup/18vl70pf_1_1.full tag=TAG20210121T173323 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:25
Finished backup at 2021-01-21 17:35:04

Starting Control File and SPFILE Autobackup at 2021-01-21 17:35:05
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-09 comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 17:35:06

可以发现在第三次备份的时候，直接跳过了 5/6/8/16号数据文件（只读），采用了N+1，不再创建额外的副本

　　3. 设备类型

　　　　RMAN> CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default  ---  可以是磁盘（DISK）,或者是磁带（STB）,默认是磁盘

　　4. 控制文件是否自动备份

　　　　RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON; # default --- 默认是打开的，当设置成OFF，在备份system表空间时，也会自动备份控制文件和SPFILE

　　5. 控制文件备份路径与格式

　　　　RMAN> CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default  --- format 指明备份文件的路径和文件名 %F只能用在备份控制文件中

　　　　官文：https://docs.oracle.com/en/database/oracle/oracle-database/19/bradv/configuring-rman-client-basic.html#GUID-C64AE090-0749-43EA-92C4-69DC6201A15F 

　　6. 并行度

　　　　RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default  ----- 如果在RUN{}中指定了通道配置，将覆盖掉配置参数中指定的默认并行度

并行度为1时，只开辟一个通道
RMAN> backup datafile 16 format '/u01/app/oracle/backup/%U.16bak';

Starting backup at 2021-01-21 18:34:53
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00016 name=/u01/app/oracle/oradata/OCP12C/hehe01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 18:34:53
channel ORA_DISK_1: finished piece 1 at 2021-01-21 18:34:54
piece handle=/u01/app/oracle/backup/1avl74ad_1_1.16bak tag=TAG20210121T183453 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2021-01-21 18:34:54

Starting Control File and SPFILE Autobackup at 2021-01-21 18:34:54
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-0a comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 18:34:56

RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;

new RMAN configuration parameters:
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
new RMAN configuration parameters are successfully stored
released channel: ORA_DISK_1
并行度设置成2，则开辟两个通道
RMAN> backup datafile 16 format '/u01/app/oracle/backup/%U.16bak';

Starting backup at 2021-01-21 18:35:25
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=25 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=1 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00016 name=/u01/app/oracle/oradata/OCP12C/hehe01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 18:35:27
channel ORA_DISK_1: finished piece 1 at 2021-01-21 18:35:28
piece handle=/u01/app/oracle/backup/1cvl74bf_1_1.16bak tag=TAG20210121T183526 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2021-01-21 18:35:28

Starting Control File and SPFILE Autobackup at 2021-01-21 18:35:28
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-0b comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 18:35:29

RMAN>

　　7. 备份集多路复用（印象备份不能）

　　　　RMAN> CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default ---- 最大值是4，如果为2则备份相同的两份，注意：TO STB 和 TO DISK 是独立的，不能同时以DISK 和 TAPE 多路复用

RMAN> CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 2;

new RMAN configuration parameters:
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 2;
new RMAN configuration parameters are successfully stored

RMAN> backup datafile 16 format '/u01/app/oracle/backup/%U.16bak','/u01/app/oracle/%U.16bak';

Starting backup at 2021-01-21 18:44:52
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=25 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00016 name=/u01/app/oracle/oradata/OCP12C/hehe01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 18:44:52
channel ORA_DISK_1: finished piece 1 at 2021-01-21 18:44:53 with 2 copies and tag TAG20210121T184452
piece handle=/u01/app/oracle/backup/1evl74t4_1_1.16bak comment=NONE
piece handle=/u01/app/oracle/1evl74t4_1_2.16bak comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2021-01-21 18:44:53

Starting Control File and SPFILE Autobackup at 2021-01-21 18:44:54
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-0c comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 18:44:55

RMAN> backup datafile 16 format '/u01/app/oracle/backup/%U.16bak';

Starting backup at 2021-01-21 18:45:18
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00016 name=/u01/app/oracle/oradata/OCP12C/hehe01.dbf
channel ORA_DISK_1: starting piece 1 at 2021-01-21 18:45:18
channel ORA_DISK_1: finished piece 1 at 2021-01-21 18:45:20 with 2 copies and tag TAG20210121T184518
piece handle=/u01/app/oracle/backup/1gvl74tu_1_1.16bak comment=NONE
piece handle=/u01/app/oracle/backup/1gvl74tu_1_2.16bak comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
Finished backup at 2021-01-21 18:45:20

Starting Control File and SPFILE Autobackup at 2021-01-21 18:45:20
piece handle=/u01/app/oracle/product/12.2.0.1/db_1/dbs/c-671397679-20210121-0d comment=NONE
Finished Control File and SPFILE Autobackup at 2021-01-21 18:45:21

设置成2后，可以发现在备份的时候 piece handle 会有两个路径

 

3. 分类

　　1. BACKUPSET：不备份datafile里从未使用块（HWM以上）、可以实现增量备份（可以备份到disk和tape）。如果只启用一个channel，默认会把所有备份的datafile放入到一个backupset里，并且生成一个备份片backup piece。

　　2. IMAGE COPY（映像备份）：实际上和手工cp 类似的，备份datafile所有的数据块，不能作为增量备份的基础（即0级增量备份），只能备份到disk，不能备份到tape，因可以省略还原步骤，所以恢复数据库速度快