使用Oracle自带的备份恢复工具RMAN(Recovery Manager)具有以下几种优势：
-
支持增量备份
-
能自动管理备份文件
-
自动化备份与恢复
-
备份的文件有效性检查
配置快闪恢复区（flash recovery area）
快闪恢复区是存储备份和恢复数据文件以及相关信息的存储区。需要设置两个参数：db_recovery_file_dest_size(快闪恢复区的最大容量)，db_recovery_file_dest(快闪恢复区所在的路径)。
查看快闪恢复区信息：
|
1
2
3
4
5
|
SQL> show parameter db_recovery_file_dest;
NAME
TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /data/app/oracle/recovery_area
db_recovery_file_dest_size big
integer
3882M
|
修改快闪恢复区大小：
|
1
2
3
4
5
6
7
|
SQL>
alter
system
set
db_recovery_file_dest_size=2g;
System altered.
SQL> show parameter db_recovery_file_dest;
NAME
TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /data/app/oracle/recovery_area
db_recovery_file_dest_size big
integer
2G
|
查看使用情况：
|
1
2
3
4
5
6
7
|
SQL>
select
name
,space_limit,space_used,number_of_files
from
v$recovery_file_dest;
NAME
--------------------------------------------------------------------------------
SPACE_LIMIT SPACE_USED NUMBER_OF_FILES
----------- ---------- ---------------
/data/app/oracle/recovery_area
2147483648 0 0
|
显示没有使用。
也可以使用此命令查看详细信息：
|
1
|
SQL>
select
file_type,percent_space_used,percent_space_reclaimable,number_of_files
from
v$flash_recovery_area_usage;
|
建立RMAN到数据库的连接
创建rman用户，并授权：
|
1
2
3
4
5
6
7
8
|
[oracle@
temp
-test oracle]$ sqlplus /nolog
SQL>
connect
/
as
sysdba
Connected.
SQL>
create
user
rman identified
by
oracle;
User
created.
SQL>
grant
resource,
connect
,dba
to
rman;
Grant
succeeded.
SQL> quit
|
使用rman用户登录RMAN:
|
1
2
3
4
5
|
[oracle@
temp
-test oracle]$ rman target rman/oracle
Recovery Manager: Release 11.2.0.1.0 - Production
on
Fri Nov 3 16:59:27 2017
Copyright (c) 1982, 2009, Oracle
and
/
or
its affiliates.
All
rights reserved.
connected
to
target
database
: ORCL (DBID=1486802665)
RMAN>
|
也可以使用如下方式登录：
|
1
2
3
4
5
6
|
[oracle@
temp
-test oracle]$ rman
Recovery Manager: Release 11.2.0.1.0 - Production
on
Fri Nov 3 17:00:35 2017
Copyright (c) 1982, 2009, Oracle
and
/
or
its affiliates.
All
rights reserved.
RMAN>
connect
target system/rman
connected
to
target
database
: ORCL (DBID=1486802665)
RMAN>
connect
target rman/oracle
|
也可以使用操作系统认证连接RMAN：
|
1
2
3
4
5
|
[oracle@
temp
-test oracle]$ rman target /
Recovery Manager: Release 11.2.0.1.0 - Production
on
Fri Nov 3 17:02:52 2017
Copyright (c) 1982, 2009, Oracle
and
/
or
its affiliates.
All
rights reserved.
connected
to
target
database
: ORCL (DBID=1486802665)
RMAN>
|
配置RMAN
查看RMAN的配置参数：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
RMAN> show
all
;
using target
database
control file
instead
of
recovery catalog
RMAN configuration parameters
for
database
with
db_unique_name ORCL 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 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 ARCHIVELOG DELETION POLICY
TO
NONE; #
default
CONFIGURE SNAPSHOT CONTROLFILE
NAME
TO
'/data/app/oracle/product/11.2.0/dbhome_1/dbs/snapcf_orcl.f'
; #
default
|
参数含义：
CONFIGURE RETENTION POLICY TO REDUNDANCY 1
保留的备份副本数量，表示只保留一个数据文件的副本，并且保留最新的备份副本。
CONFIGURE DEFAULT DEVICE TYPE TO DISK
数据文件默认备份到磁盘上，也可以是其他设备如磁带（sbt）
CONFIGURE BACKUP OPTIMIZATION OFF
不使用备份优化，启用备份优化的作用是如果已经备份了某个文件的相同版本，则不会再备份该文件。，只保留一份备份文件。
CONFIGURE CONTROLFILE AUTOBACKUP OFF
不启动控制文件的自动备份，修改为ON之后，如果数据库结构发生变化或者在备份数据库过程中，控制文件会自动再备份到指定目录下
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET
备份通道数量为1，默认使用备份集的方式。通道数量越多，执行任务时间越短。
如果要修改参数，可以执行如下命令：
开启备份优化：
|
1
2
3
4
|
RMAN> CONFIGURE BACKUP OPTIMIZATION
ON
;
new RMAN configuration parameters:
CONFIGURE BACKUP OPTIMIZATION
ON
;
new RMAN configuration parameters are successfully stored
|
设置备份类型为Copy，也就是映像模式:
|
1
2
3
4
|
RMAN> CONFIGURE DEVICE TYPE DISK BACKUP TYPE
TO
COPY;
new RMAN configuration parameters:
CONFIGURE DEVICE TYPE DISK BACKUP TYPE
TO
COPY PARALLELISM 1;
new RMAN configuration parameters are successfully stored
|
备份控制文件到快闪恢复区：
|
1
2
3
4
5
6
7
8
|
RMAN> backup
current
controlfile;
Starting backup
at
03-NOV-17
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile copy
copying
current
control file
output
file
name
=/data/app/oracle/recovery_area/ORCL/controlfile/o1_mf_TAG20171103T180113_dzrhm9vk_.ctl tag=TAG20171103T180113 RECID=3 STAMP=959104874
channel ORA_DISK_1: datafile copy complete, elapsed
time
: 00:00:01
Finished backup
at
03-NOV-17
|
如果没有指定快闪恢复区也可以用手动指定路径：
将快闪恢复区改为test目录
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
SQL> connect
/as
sysdba
Connected.
SQL> show parameter db_recovery_file_dest;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string
/data/app/oracle/recovery_area
db_recovery_file_dest_size big integer 2G
SQL> alter system
set
db_recovery_file_dest=
'/data/app/oracle/test'
;
System altered.
SQL> show parameter db_recovery_file_dest;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string
/data/app/oracle/test
db_recovery_file_dest_size big integer 2G
|
配置控制文件备份的磁盘类型和备份目录，路径以%F结尾：
|
1
2
3
4
5
|
RMAN> configure controlfile autobackup
format
for
device
type
disk to
'/data/app/oracle/test/%F'
;
new RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO
'/data/app/oracle/test/%F'
;
new RMAN configuration parameters are successfully stored
|
RMAN脱机备份
RMAN脱机备份需要关闭数据库，启动数据库到mount状态。
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
[oracle@
temp
-test oracle]$ sqlplus /nolog
SQL>
connect
/
as
sysdba
Connected.
SQL> shutdown immediate;
Database
closed.
Database
dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.
Total System
Global
Area 1586708480 bytes
Fixed
Size
2213736 bytes
Variable
Size
939526296 bytes
Database
Buffers 637534208 bytes
Redo Buffers 7434240 bytes
Database
mounted.
SQL> quit
|
进入RMAN，备份数据：
先查看数据备份的默认参数，备份方式（copy或backupset），和备份格式(disk 或其他)
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
RMAN> show
all
;
using target
database
control file
instead
of
recovery catalog
RMAN configuration parameters
for
database
with
db_unique_name ORCL are:
CONFIGURE RETENTION POLICY
TO
REDUNDANCY 1; #
default
CONFIGURE BACKUP OPTIMIZATION
ON
;
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 BACKUP TYPE
TO
COPY PARALLELISM 1;
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 ARCHIVELOG DELETION POLICY
TO
NONE; #
default
CONFIGURE SNAPSHOT CONTROLFILE
NAME
TO
'/data/app/oracle/product/11.2.0/dbhome_1/dbs/snapcf_orcl.f'
; #
default
|
执行备份命令使用copy方式，映像复制整个库：
|
1
|
RMAN> backup
as
copy
database
;
|
如果是使用默认的backupset模式，可以使用：
|
1
|
RMAN> backup
as
compressed backupset
database
;
|
备份完成后，打开数据库：
|
1
2
|
RMAN> sql
'alter database open'
;
sql statement:
alter
database
open
|
RMAN联机备份整个数据库
联机备份必须要设置快闪恢复区，快闪恢复区要足够大，并且数据库要置于归档模式。在数据库进行备份的同时，可以进行DML操作，可以正常读取，新的DML操作记录会在重做日志文件中,如果备份时间很长，而且在这个期间产生了大量的数据变化，重做日志会切换从而将这些变化的数据写到归档日志文件中。这里的归档日志就类似于mysql的binlog,在出现介质故障的时候，使用备份和归档日志记录和完成数据的全部恢复。
查看数据库归档模式是否开启，当前属于关闭状态：
|
1
2
3
4
5
6
|
SQL> archive log list;
Database log mode No Archive Mode
Automatic archival Disabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 22
Current log sequence 24
|
开启日志归档：
|
1
2
3
4
5
6
|
SQL> alter database archivelog;
alter database archivelog
*
ERROR at line 1:
ORA-01126: database must be mounted
in
this instance and not
open
in
any
instance
|
日志归档必须在mount模式，关闭数据库启动到mount模式，开启归档模式：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
SQL>
shutdown
immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
mount
;
ORACLE instance started.
Total System Global Area 1586708480 bytes
Fixed Size 2213736 bytes
Variable Size 1040189592 bytes
Database Buffers 536870912 bytes
Redo Buffers 7434240 bytes
Database mounted.
SQL> alter database archivelog;
Database altered.
SQL> alter database
open
;
Database altered.
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 22
Next log sequence to archive 24
Current log sequence 24
|
使用RMAN联机备份数据库：
|
1
|
RMAN> backup as compressed backupset database plus archivelog delete all input;
|
使用备份集格式进行备份，并采用压缩的方式，压缩比例大概为5：1。备份数据文件，同时也备份归档日志文件，备份完成之后会将已经备份的归档日志文件从存储目录中删除，清除归档空间。
备份表空间：
|
1
2
3
4
5
6
7
8
|
RMAN> backup tablespace
users
;
Starting backup at 06-NOV-17
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile copy
input datafile
file
number=00004 name=
/data/app/oracle/oradata/orcl/users01
.dbf
output
file
name=
/data/app/oracle/test/ORCL/datafile/o1_mf_users_dzzxzmxv_
.dbf tag=TAG20171106T134939 RECID=12 STAMP=959348980
channel ORA_DISK_1: datafile copy complete, elapsed
time
: 00:00:01
Finished backup at 06-NOV-17
|
使用压缩：
|
1
|
RMAN> backup as compressed backupset tablespace
users
;
|
使用RMAN备份数据文件，%U表示自动分配一个唯一的命名：
|
1
|
RMAN> backup as backupset datafile 1
format
'/data/app/backup/datafile_1_%U'
;
|
清除命令，慎用
清除旧的备份文件set格式：
|
1
2
3
|
RMAN> delete obsolete;
RMAN> crosscheck backupset;
RMAN> delete expired backupset;
|
清楚旧的备份文件和所有备份，copy模式：
|
1
2
3
4
|
RMAN> list datafilecopy all;
RMAN> delete expired backupcopy;
RMAN> crosscheck datafilecopy all;
RMAN> delete expired backupcopy;
|
如果是由于快闪恢复区容量限制，可以修改快闪恢复区的路径和容量：
|
1
|
SQL> alter system
set
db_recovery_file_dest=
'/data/app/oracle/test'
;
|
|
1
|
SQL>
alter
system
set
db_recovery_file_dest_size=10g;
|
RMAN增量备份
使用backup database时，都是全库备份，每次这样备份很耗时也占用磁盘空间，RMAN的增量备份就能解决这些问题。
这里有两种备份级别，级别0备份为全库备份，级别1的备份为增量备份，一般情况下需要对数据进行0级别的备份之后在进行级别1的增量备份。
|
1
|
RMAN> backup incremental level 0 database;
|
级别1的差异增量备份：
|
1
|
RMAN> backup incremental level 1 database;
|
对映像副本进行增量备份
|
1
2
3
4
|
RMAN> run {
2> backup incremental level 1
for
recover of copy with tag
'incr_copy_backup'
database;
3> recover copy of database with tag
'incr_copy_backup'
;
4> }
|
每次执行这条命令，就可以使用映像的方式对数据库进行增量备份。
本文转自 酥心糖 51CTO博客，原文链接:http://blog.51cto.com/tryingstuff/1979382
