本系列宗旨:真正掌握OCP考试中所考察的技能,坚决不做Paper OCP!
实验环境:RHEL 6.4 + Oracle 11.2.0.4
OCP考点实战演练01-备份恢复篇
- 1.数据库开启归档
- 2.配置数据库的可恢复性
- 3.RMAN恢复目录
- 4.创建RMAN备份
- 5.使用RMAN备份进行恢复
- 6.用户管理的备份和恢复
- 7.其他RMAN功能
- 8.监视和调整RMAN
- 9.配置和使用闪回
- Reference
1.数据库开启归档
```
#正常关闭数据库之后,启动数据库到mount状态,开启数据库归档
SQL> shutdown immediate
SQL> startup mount
SQL> alter database archivelog;
SQL> alter database open;
SQL> archive log list
```
2.配置数据库的可恢复性
## 2.1 闪回恢复区 ##
```
#查询闪回恢复区的整体使用情况
SQL> select * from v$recovery_file_dest;
查询闪回恢复区的详细使用情况
SQL> select * from v$flash_recovery_area_usage;
## 2.2 配置多个归档日志文件目标 ##
11g推荐使用log_archive_dest_n来配置多个归档日志文件目标:
设定两个本地归档文件目标
SQL> alter system set log_archive_dest_1 = 'LOCATION=/u01/oradb_arch1';
SQL> alter system set log_archive_dest_2 = 'LOCATION=/u01/oradb_arch2';
问题:定义了log_archive_dest_1 就不再使用闪回恢复区了?
实验证明:定义了log_archive_dest_1后,就不会再使用闪回恢复区存放归档日志。
问题:多个归档目标是否需要都成功?
实验证明:有一个定义归档最小成功路径数量,LOG_ARCHIVE_MIN_SUCCEED_DEST参数。需要注意,如果某个归档目标是MANDATORY的,那么该归档目标必须归档成功。
alter system set log_archive_min_succeed_dest=2;
## 2.3 保留策略 ##
保留策略设定为2份冗余
RMAN> CONFIGURE RETENTION POLICY TO REDUNDANCY 2;
保留策略设定为4天恢复窗口
RMAN> CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 4 DAYS;
<h1 id="3">3.RMAN恢复目录</h1>
参考:
- [RMAN Catalog创建、配置和管理](http://www.cnblogs.com/jyzhao/p/4864694.html)
<h1 id="4">4.创建RMAN备份</h1>
完整备份,完全备份,增量备份[0级备份|1级差异(默认)|1级累积(cumulative)]
## 4.1 FORMAT子句中的替代变量 ##
format 'rman_%d_%T_%s_%p.backupset'
这样的备份集名称最易识别,生成文件名示例:rman_ORADB_20151030_27_1.backupset
如果多重备份,加一个%c
即: %d_%T_%s_%p_%c
## 4.2 完全备份 ##
备份users表空间(备份集)
RMAN> backup as backupset format '/u01/oradb_bak/rman_%d_%T_%s_%p.backupset' tablespace users;
不显示指定as backupset, 默认也是备份集形式备份
RMAN> backup format '/u01/oradb_bak/rman_%d_%T_%s_%p.backupset' tablespace users;
可以备份为压缩的备份集,节省空间,但同时备份和恢复时会消耗CPU资源压缩和解压。
RMAN> backup as compressed backupset tablespace system;
## 4.3 增量备份 ##
0级备份
RMAN> backup incremental level 0 tablespace users;
1级差异备份
RMAN> backup incremental level 1 tablespace users;
1级累积备份
RMAN> backup incremental level 1 cumulative tablespace users;
0级copy
RMAN> backup incremental level 0 as copy tablespace system;
**块更改跟踪文件**
开启块更改跟踪
SQL> alter database enable block change tracking;
查看块更改跟踪文件
SQL> select filename from v$block_change_tracking;
关闭块更改跟踪
SQL> alter database disable block change tracking;
## 4.4 多重备份 ##
备份为2份副本
RMAN> backup as compressed backupset copies 2 tablespace users format '/u01/oradb_bak/rman_bak01_%d_%T_%s_%p.backupset', '/u01/oradb_bak/rman_bak02_%d_%T_%s_%p.backupset';
RMAN> backup as compressed backupset tablespace users format '/u01/oradb_bak/rman_bak01_%d_%T_%s_%p_%c.backupset', '/u01/oradb_bak/rman_bak02_%d_%T_%s_%p_%c.backupset';
**配置磁盘通道的默认路径**
RMAN> configure channel device type disk format '/u01/oradb_bak/rman01_%U.backupset', '/u01/oradb_bak/rman02_%U.backupset';
## 4.5 备份集的备份 ##
RMAN> backup device type disk backupset all;
保存时间超过2周的备份集都会备份在磁带上,并且从磁盘上删除它们。
RMAN> backup device type sbt backupset completed before 'sysdate-14' delete input;
**只读表空间备份**
如果优化选项没有开启,默认是备份只读表空间的,但可以强制RMAN忽略只读表空间的备份,指定`SKIP READONLY`选项。
## 4.6 创建长期保留的归档备份 ##
11g版本的新特性:
保存1年的
RMAN> backup as compressed backupset database format '/u01/oradb_bak/archbak_%d_%T_%p_%s_%c' tag save1year keep until time 'sysdate+365';
备份输出信息可以清楚看到backup will be obsolete on date 2016-11-01 10:28:48
类似这样的提示信息。也就是一年后才被标记为obsolete。
保存永久的
RMAN> backup as compressed backupset database format '/u01/oradb_bak/archbak_%d_%T_%p_%s_%c' tag saveforever keep forever;
同样,备份输出信息可以看到backup will never be obsolete
这样的提示信息。也就是永远都不会被标记为obsolete。
修改归档备份的保留期限
RMAN> change backup tag 'SAVEFOREVER' nokeep;
RMAN> change backup tag 'SAVEFOREVER' keep forever;
change其他用法,例如归档日志路径变更
RMAN> HOST '/bin/mv $ORACLE_HOME/dbs/*.arc /disk2/archlog/';
RMAN> CHANGE ARCHIVELOG ALL UNCATALOG;
RMAN> CATALOG START WITH '/disk2/archlog' NOPROMPT;
特别注意:不可以使用闪回恢复区来存储归档备份。
## 4.7 创建多段、压缩和加密备份 ##
**11g新特性:多段备份**
适用于大文件表空间的备份
RMAN> backup tablespace users section size 1M;
注:同时可以分配多个磁盘和磁带通道,以并行方式备份每段数据文件。
验证备份也可以指定`section size`
RMAN> validate tablespace users;
RMAN> validate tablespace users section size 1M;
相关数据字典视图
目标数据库
v$backup_set
v$backup_datafile
恢复目录
rc_backup_set
rc_backup_datafile
**压缩备份**
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default
**加密备份**
分为三种:透明加密、密码加密、双模式加密。
主要介绍下透明加密:
a) 配置sqlnet.ora文件
ENCRYPTION_WALLET_LOCATION = (SOURCE =
(METHOD = FILE)
(METHOD_DATA =
(DIRECTORY =
/etc/ORACLE/WALLETS/oracle)))
b) 创建wallet
mkdir -p /etc/ORACLE/WALLETS/oracle
chown -R oracle:oinstall /etc/ORACLE
--创建wallet
--第一种方法:orapki wallet create -wallet wallet_location [-pwd password]
--第二种方法:orapki wallet create -wallet wallet_location -auto_login [-pwd password]
$ orapki wallet create -wallet /etc/ORACLE/WALLETS/oracle -pwd MyWalletPWD1
c) 打开/关闭wallet,Set Master Key
--打开wallet
ALTER SYSTEM SET ENCRYPTION WALLET OPEN IDENTIFIED BY "MyWalletPWD1";
--关闭wallet
ALTER SYSTEM SET ENCRYPTION WALLET CLOSE IDENTIFIED BY "MyWalletPWD1";
--Master key
ALTER SYSTEM SET ENCRYPTION KEY IDENTIFIED BY "MyWalletPWD1";
d) RMAN透明加密备份
-- 打开加密功能
RMAN> CONFIGURE ENCRYPTION FOR DATABASE ON;
//RMAN> set encryption identified by "MyWalletPWD1";
-- 加密备份users表空间
RMAN> backup as compressed backupset tablespace users;
-- 关闭加密功能
RMAN> CONFIGURE ENCRYPTION FOR DATABASE OFF;
## 4.8 备份报告和维护 ##
-- list
list backup summary;
list backup;
list script names;
-- report
report need backup;
report schema;
-- delete
delete obsolete;
delete backup;
delete backupset XXXXXXX;
-- crosscheck & delete
crosscheck backup;
delete expired;
<h1 id="5">5.使用RMAN备份进行恢复</h1>
参考:
- [Oracle Recovery 01 - 常规恢复之完全恢复](http://www.cnblogs.com/jyzhao/p/4710227.html)
- [Oracle Recovery 02 - 常规恢复之不完全恢复](http://www.cnblogs.com/jyzhao/p/4723994.html)
其他脚本、相关视图、命令关键字:
-- run块脚本示例
run {
recover copy of database
with tag 'inc_upd';
backup incremental level 1
for recover of copy
with tag 'inc_upd'
database;
}
-- 恢复常用视图
v$datafile
v$datafile_header
v$recover_file
v$tablespace
-- 恢复相关命令关键字
offline
online
switch
restore
recover
resetlogs
<h1 id="6">6.用户管理的备份和恢复</h1>
## 6.1 丢失临时文件 ##
如果不停机,那么增加新的临时文件,删除旧的临时文件。
select file#, name from v$tempfile;
alter tablespace temp add tempfile '/u01/oradata/ORADB/datafile/temp01.dbf' size 30M;
alter tablespace temp drop tempfile '/u01/oradata/ORADB/datafile/o1_mf_temp_c2v10px4_.tmp';
select file#, name from v$tempfile;
如果停机,那么重启库时会自动创建临时文件(前提是存放临时文件的目录还可用且有读写权限)。
当然,丢失临时文件是没有必要停机恢复的,完全可以在线来做。
## 6.2 丢失重做日志组(重点) ##
参考:
- [Oracle丢失重做日志的几种场景恢复](http://www.cnblogs.com/jyzhao/p/4935592.html)
## 6.3 丢失口令文件 ##
orapwd命令重建口令文件
$ orapwd
Usage: orapwd file= entries= force=<y/n> ignorecase=<y/n> nosysdba=<y/n>
where
file - name of password file (required),
password - password for SYS will be prompted if not specified at command line,
entries - maximum number of distinct DBA (optional),
force - whether to overwrite existing file (optional),
ignorecase - passwords are case-insensitive (optional),
nosysdba - whether to shut out the SYSDBA logon (optional Database Vault only).
There must be no spaces around the equal-to (=) character.
## 6.4 查看恢复相关视图 ##
**6.4.1 需要恢复的文件**
set linesize 1000
select file#, d.name d_name, t.name t_name, status, error
from v$recover_file r
join v$datafile d using(file#)
join v$tablespace t using(ts#);
结果示例:
FILE# D_NAME T_NAME STATUS ERROR
5 /u01/oradata/ORADB/datafile/o1_mf_tbs_test_c3mdft5o_.dbf TBS_TEST ONLINE FILE NOT FOUND
**6.4.2 查看恢复文件需要的归档日志**
SQL> select archive_name from v$recovery_log;
## 6.5 备份users表空间 ##
alter tablespace users begin backup;
!cp /xxxx/users01.dbf /xxxx/users01.dbf.bak
alter tablespace users end backup;
<h1 id="7">7.其他RMAN功能</h1>
## 7.1 使用RMAN创建复制数据库 ##
参考:
- [使用RMAN创建复制数据库](http://www.cnblogs.com/jyzhao/p/4939901.html)
## 7.2 表空间基于时间点的恢复(TSPITR) ##
参考:
- [表空间基于时间点的恢复(TSPITR)](http://www.cnblogs.com/jyzhao/p/4956220.html)
<h1 id="8">8.监视和调整RMAN</h1>
## 8.1 监视RMAN会话和作业 ##
--v$session和v$process
select sid, spid, client_info
from v$process p join v$session s on (p.addr = s.paddr)
where client_info like '%rman%';
--run 块中可以指定command id ,便于区分。
run {
set command id to 'backup tbs users';
backup tablespace users;
}
--v$session_longops
select sid, serial#, opname, context, sofar, totalwork
from v$session_longops
where opname like 'RMAN%'
and sofar <> totalwork;
## 8.2 RMAN会话的调试 ##
示例:rman debug trace进入RMAN,只在备份表空间dbs_d_test时,开启debug,生成跟踪文件rman_debug.txt。
rman target / debug trace rman_debug.txt
run {
debug off;
backup tablespace dbs_d_jingyu;
debug on;
backup tablespace dbs_d_test;
}
执行过程输出:
$ rman target / debug trace rman_debug.txt
Recovery Manager: Release 11.2.0.4.0 - Production on Thu Nov 12 16:53:36 2015
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
RMAN-06005: connected to target database: ORADB (DBID=2647366668)
RMAN> run {
2> debug off;
3> backup tablespace dbs_d_jingyu;
4> debug on;
5> backup tablespace dbs_d_test;
6> }
Debugging turned off
Starting backup at 2015-11-12 16:54:33
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=47 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=00005 name=/u01/oradata/ORADB/datafile/o1_mf_dbs_d_ji_c45slpl1_.dbf
channel ORA_DISK_1: starting piece 1 at 2015-11-12 16:54:34
channel ORA_DISK_1: finished piece 1 at 2015-11-12 16:54:35
piece handle=/u01/oradb_bak/rman_ORADB_20151112_184_1_1.backupset tag=TAG20151112T165434 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2015-11-12 16:54:36
Starting Control File and SPFILE Autobackup at 2015-11-12 16:54:36
piece handle=/u01/app/oracle/fast_recovery_area/ORADB/autobackup/2015_11_12/o1_mf_s_895596876_c48nyd6l_.bkp comment=NONE
Finished Control File and SPFILE Autobackup at 2015-11-12 16:54:37
RMAN-03036: Debugging set to level=9, types=ALL
RMAN-03090: Starting backup at 2015-11-12 16:54:37
RMAN-12016: using channel ORA_DISK_1
RMAN-08008: channel ORA_DISK_1: starting full datafile backup set
RMAN-08010: channel ORA_DISK_1: specifying datafile(s) in backup set
RMAN-08522: input datafile file number=00007 name=/u01/oradata/ORADB/datafile/o1_mf_dbs_d_te_c45ssxmd_.dbf
RMAN-08038: channel ORA_DISK_1: starting piece 1 at 2015-11-12 16:54:37
RMAN-08044: channel ORA_DISK_1: finished piece 1 at 2015-11-12 16:54:38
RMAN-08530: piece handle=/u01/oradb_bak/rman_ORADB_20151112_186_1_1.backupset tag=TAG20151112T165437 comment=NONE
RMAN-08540: channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
RMAN-03091: Finished backup at 2015-11-12 16:54:38
RMAN-03090: Starting Control File and SPFILE Autobackup at 2015-11-12 16:54:38
RMAN-08503: piece handle=/u01/app/oracle/fast_recovery_area/ORADB/autobackup/2015_1
RMAN> exit
Recovery Manager complete.
[oracle@JY-DB01 ~]$ pwd
/home/oracle
[oracle@JY-DB01 ~]$ ls -lh rman*
-rw-r--r--. 1 oracle oinstall 178K Nov 12 16:54 rman_debug.txt
## 8.3 调整RMAN ##
**确定备份和还原的步骤**
RMAN备份在通道中执行任务时,经历3个主要阶段:
- 读阶段:通道将数据块读入输入缓冲区。
- 复制阶段:通道将块从输入缓冲区复制到输出缓冲区,并根据需要执行其他处理(验证、压缩、加密都在此阶段)。
- 写阶段:通道将输出缓冲区中的块写入到磁盘或磁带。
每天或或每小时创建一次映像副本会增加备份时间,但却可以极大的减少恢复时间。
**并行执行备份集**
分配多个通道,分配的通道数量不得超过物理设备的数量。还可以给每个数据文件分配特定通道。
run {
allocate channel c1 device type disk;
allocate channel c2 device type disk;
allocate channel c3 device type disk;
backup incremental level 0
(datafile 1,2,9 channel c1)
(datafile 3,8,7 channel c2)
(datafile 4,5,6 channel c3)
as compressed backupset;
}
最多为每个RMAN会话分配225个通道,每个通道最多可以并行读取64个数据文件。
**RMAN多路复用操作**
主要通过FILESPERSET和MAXOPENFILES控制多路复用。
可用公式min(MAXOPENFILES,min(FILESPERSET,files_per_channel))
注:不能多路复用映像副本。
**调整RMAN通道**
使用MAXPIECESIZE,RATE和MAXOPENFILES参数调整RMAN通道。
**调整BACKUP命令**
使用MAXPIECESIZE,FILESPERSET,MAXOPENFILES和BACKUP DURATION参数调整BACKUP命令。
可以将BACKUP参数BACKUP DURATION设置为MINIMIZE TIME以便尽量加快备份速度,也可以将此参数设置为MINIMIZE LOAD以减少数据库的I/O请求。
**配置LARGE_POOL_SIZE**
可以配置初始化参数LARGE_POOL_SIZE降低RMAN备份对共享池的争用。
## 8.4 为异步I/O配置RMAN ##
**了解异步I/O和同步I/O**
同步I/O必须等到完成一个I/O请求后才能启动另一个I/O请求。异步备份操作无需等待。
将初始化参数BACKUP_TAPE_IO_SLAVES设置为TURE,以便为异步操作配置磁带备份。
初始化参数DBWR_IO_SLAVES设置时,会模拟异步I/O操作。
**监视异步I/O**
v$backup_async_io
LONG_WAITS与IO_COUNT的比率越低越好;
SHORT_WAIT_TIME_TOTAL或LONG_WAIT_TIME_TOTAL正常值应为0。
**监视同步I/O**
v$backup_sync_io
DISCRETE_BYTES_PER_SECOND列与磁带输出设备的最大比率做对比,以便确定调整时机。
<h1 id="9">9.配置和使用闪回</h1>
参考:
- [Oracle配置和使用闪回](http://www.cnblogs.com/jyzhao/p/4968804.html)
<h1 id="10">Reference</h1>
- OCP 认证考试指南 (1Z0-053)[M]. 清华大学出版社, 2010.