搭建记录：duplicate搭建oracle rac到单实例搭建物理DG_V7

原创徐sir 2023-10-17

2499

以前一直也用这个文档来在小型的生产环境搭建ADG，经过了多轮的改版，之前上墨天轮上发布过6.0的版本
经过多次检查发现还是有修改的空间，经过一部分校正，再发布第7版。如果有错误还请大家帮忙指出，我再进行修改。

修定记录

序号	修订日期	更新后版本	修定内容
1	2019年1月5日	V1.0	文档创建
2	2019年1月11日	V2.0	第1次增加“实施注意事项”
3	2019年4月4日	V3.0	1、“实施注意事项”内增加6关于用户变量的注意事项 2、修复错误5、6部分convert参数，主库的书写格式应该是:’备库位置’,’主库位置’;备库的书写格式应该是：’主库位置‘,’备库位置‘
4	2019年9月2日	V4.0	alter system set log_archive_dest_2='service=orcldg async noaffirm valid_for=(online_logfiles,primary_role) db_unique_name=orcldg' scope=both sid='*'; 修正错误，上段内容中scope=both，旧文档内容为scope=spfile
5	2019年11月2日	V5.0	注意rman复制时nofilenamecheck参数如果主备库路径不一致要加该参数！！还有一定要注意生产库的compatible版本
6	2023年2月23日	V6.0	第6节，注意db_file_convert参数和db_files参数修改
7	2023年12月25日	V70	修复部分错别字、描述有歧义的问分。第9节增加如何开启并行的方法增加第16节，快照数据库，实施注意改为17节。删除第17节与11G无关的或错误的描述

修定记录 1

Duplicate搭建RAC到单实例ADG（11G） 2

0、测试环境信息 2

1、主库归档 3

2、主库force logging模式开启 3

3、主库创建standby redo log 文件 3

9、RMAN复制数据库到备库，进行同步 8

15、强制切换（会丢数据，极端环境操作） 16

Duplicate搭建RAC到单实例ADG（11G）

0、测试环境信息

主库基本环境

主机	CPU	内存	ORACLE_HOME	实例名	Db_name	db_unique_name
RAC1	1	4	/u01/app/oracle/product/11.2.0/dbhome_1	orcl1	orcl	orcl
RAC2	1	4	/u01/app/oracle/product/11.2.0/dbhome_1	orcl2	orcl	orcl

主库文件路径环境

主机

数据文件路径

控制文件

归档日志文件

RAC1

+DATA/orcl/datafile

+DATA/orcl/tempfile

+DATA/orcl/controlfile

+DATA/orcl/archivelog

RAC2

主库HOSTS文件：

192.168.56.10 rac1
192.168.56.11 rac2
192.168.56.12 rac1-vip
192.168.56.13 rac2-vip
192.168.56.14 rac-scan
10.10.10.10 rac1-priv
10.10.10.11 rac2-priv
192.168.56.20 oracle复制

备库环境设计：

/u01/app/oracle/oradata/orcldg/datafile	备库数据文件存放路径
/u01/app/oracle/oradata/orcldg/onlinelog	备库联机日志文件文件存放路径
/u01/app/oracle/oradata/orcldg/tempfile	备库临时表空间文件存放路径
/u01/app/oracle/oradata/orcldg/controlfile	备库控制文件存放路径
/u01/app/oracle/oradata/orcldg/archivelog	备库归档文件存放路径
/u01/app/oracle/admin/orcldg/adump	备库相关日志存放路径
/u01/app/oracle/admin/orcldg/dpdump	备库相关日志存放路径
/u01/app/oracle/admin/orcldg/hdump	备库相关日志存放路径
/u01/app/oracle/admin/orcldg/pfile	备库相关日志存放路径
/u01/app/oracle/fast_recover_area	备库闪回空间放路径

备库相关名称：
db_unique_name=orcldg
db_name=orcl
instance_name=orcldg复制

1、主库归档开启

在RAC1节点执行

sqlplus / as sysdba
alter system set log_archive_dest_1=’location=+DATA’;
exit复制

停库immediate

srvctl stop database -d orcl -o immediate;复制

启动RAC1节点实例到mount模式

srvctl start database -d orcl -n rac1 -o mount复制

设置RAC1节点数据库archivelog

sqlplus / as sysdba
alter database archivelog;
alter databae open;复制

启动RAC2节点实例

srvctl start instance -d orcl -I orcl2 -o open复制

确认是否为归档开启

sqlplus / as sysdba
archive log list复制

2、主库force logging模式开启

在节点RAC1执行，查看数据库的模式：

select log_mode,open_mode,protection_mode,database_role,switchover_status,guard_status,force_logging from v$database;复制

在节点RAC1上执行：

alter database force logging;复制

3、主库创建standby redo log 文件

主库RAC1节点sqlplus执行查看现有日志组情况

col member format a50;
select a.thread#,a.group#,a.bytes/1024/1024,b.member from v$log a,v$logfile b where a.group#=b.group#;复制

每个 thread 都需要创建，standby redo log 比 redo log 多一组,大小相同

alter database add standby logfile thread 1 group 11 ('+DATA') size 50m;
alter database add standby logfile thread 1 group 12 ('+DATA') size 50m;
alter database add standby logfile thread 1 group 13 ('+DATA') size 50m;
alter database add standby logfile thread 1 group 14 ('+DATA') size 50m;
alter database add standby logfile thread 1 group 15 ('+DATA') size 50m;
alter database add standby logfile thread 2 group 21 ('+DATA') size 50m;
alter database add standby logfile thread 2 group 22 ('+DATA') size 50m;
alter database add standby logfile thread 2 group 23 ('+DATA') size 50m;
alter database add standby logfile thread 2 group 24 ('+DATA') size 50m;
alter database add standby logfile thread 2 group 25 ('+DATA') size 50m;复制

创建完查看日志组

select group#,type,member from v$logfile order by 2;复制

4、备库创建目录

[oracle@oracle ~]$ cd $ORACLE_BASE
[oracle@oracle oracle]$ mkdir -p oradata/orcldg/datafile
[oracle@oracle oracle]$ mkdir -p oradata/orcldg/onlinelog
[oracle@oracle oracle]$ mkdir -p oradata/orcldg/tempfile
[oracle@oracle oracle]$ mkdir -p oradata/orcldg/controlfile
[oracle@oracle oracle]$ mkdir -p oradata/orcldg/archivelog
[oracle@oracle oracle]$ cd $ORACLE_BASE
[oracle@oracle oracle]$ ls
cfgtoollogs checkpoints diag oradata product
[oracle@oracle oracle]$ mkdir -p admin/orcldg/adump
[oracle@oracle oracle]$ mkdir -p admin/orcldg/dpdump
[oracle@oracle oracle]$ mkdir -p admin/orcldg/hdump
[oracle@oracle oracle]$ mkdir -p admin/orcldg/pfile
[oracle@oracle oracle]$ mkdir -p /u01/app/oracle/fast_recover_area复制

5、参数修改

show parameter db_name

show parameter db_unique_name

DB_NAME备库要与主库保持一致，

DB_UNIQUE_NAME要有所区别，不能一样，

参数DG_CONFIG和LOG_ARCHIVE_CONFIG中会用到db_unique_name

Log_archive_dest_2里的service=后面跟的是服务名，就是写到TNSNAMES.ORA里的

主库修改参数如下，在RAC1节点执行

alter system set log_archive_config='dg_config=(orcl,orcldg)' sid='*';
alter system set log_archive_dest_1='location=+DATA valid_for=(all_logfiles,all_roles) db_unique_name=orcl' sid='*';
alter system set log_archive_dest_2='service=orcldg async noaffirm valid_for=(online_logfiles,primary_role) db_unique_name=orcldg' scope=both sid='*';
alter system set standby_file_management=auto scope=both sid='*';
alter system set fal_client='orcl' scope=both sid='*';
alter system set fal_server='orcldg' scope=both sid='*';
alter system set log_archive_max_processes=10 scope=both;
alter system set db_file_name_convert='/u01/app/oracle/oradata/orcldg/datafile','+DATA/orcl/datafile','/u01/app/oracle/oradata/orcldg/tempfile','+DATA/orcl/tempfile' scope=spfile sid='*';
alter system set log_file_name_convert='/u01/app/oracle/oradata/orcldg/onlinelog','+DATA/orcl/onlinelog' scope=spfile sid='*';复制

关闭数据库使参数生效

（这里关库重启主要是为了让db_file_name_convert和log_file_name_convert立即生效！这两个参数如果这里不配置也可以！等需要的时候再配置。如果配置了该参数没有立即重启库，以后可能会出现1个实例崩溃后无法正常启动，提示参数不致！！！！）

srvctl stop database -d orcl -o immediate;复制

启动数据库实例

srvctl start database -d orcl -o open;复制

6、创建备库参数文件及口令文件

在主库RAC1节点执行，拷贝口令文件及参数文件到备库

[oracle@rac1 ~]$ cd $ORACLE_HOME/dbs
[oracle@rac1dbs]$scp orapworcl1 oracle@oracle:/u01/app/oracle/product/11.2.0/db_1/dbs复制

主库两个节点分别拷贝自己的口令文件到对方的dbs目录下

在备库重命名口令文件

[oracle@oracle admin]$ cd $ORACLE_HOME/dbs
[oracle@oracle dbs]$ ls
init.ora orapworcl1 pfileorcl.ora
[oracle@oracle dbs]$ mv orapworcl1 orapworcl复制

在备库创建参数文件，注意如下事项：

注意备库的参数文件中db_files:

参数要与生产的进行一下比较，要多于生产库的文件数量

注意db_file_name_convert参数:

如果原库的数据文件在多个路径下且有重名的数据文件情况下，此时注意修改该参数值不要在同一个文件夹下！！

修改后内容如下：

[oracle@oracle dbs]$ touch initorcldg.ora
*.audit_file_dest='/u01/app/oracle/admin/orcldg/adump'
*.audit_trail='db'
*.compatible='11.2.0.4.0'
*.control_files='/u01/app/oracle/oradata/orcldg/controlfile/control01.ctl','/u01/app/oracle/oradata/orcldg/controlfile/control02.ctl'
*.db_block_size=8192
*.db_domain=''
*.db_file_name_convert='+DATA/orcl/datafile','/u01/app/oracle/oradata/orcldg/datafile','+DATA/orcl/tempfile','/u01/app/oracle/oradata/orcldg/tempfile'
*.db_files=1024
*.log_file_name_convert= '+DATA/orcl/onlinelog','/u01/app/oracle/oradata/orcldg/onlinelog'
*.db_name='orcl'
*.db_recovery_file_dest_size=6005194752
*.db_recovery_file_dest='/u01/app/oracle/fast_recover_area'
*.diagnostic_dest='/u01/app/oracle'
*.fal_client='orcldg'
*.fal_server='orcl'
*.log_archive_config='DG_CONFIG=(orcl,orcldg)'
*.log_archive_dest_1='location=/u01/app/oracle/oradata/orcldg/archivelog valid_for=(all_logfiles,all_roles) db_unique_name=orcldg'
*.log_archive_dest_2='service=orcl ASYNC NOAFFIRM valid_for=(online_logfiles,primary_role) db_unique_name=orcl'
*.log_archive_format='%t_%s_%r.dbf'
*.open_cursors=300
*.processes=150
*.remote_login_passwordfile='exclusive'
*.standby_file_management='AUTO'
*.db_unique_name='orcldg'
*.service_names='orcldg'
*.undo_tablespace='UNDOTBS1'
*.memory_target=300m复制

7、主库监听相关创建

tnsnames.ora文件

ORCL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = rac-scan)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcl)
)
)
ORCLDG =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.20)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcldg)
)
)复制

8、备库监听相关创建

Listener.ora文件

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.20)(PORT = 1521))
)
)
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(ORACLE_HOME = /u01/app/oracle/product/11.2.0/db_1)
(SID_NAME = orcldg)
)
)复制

tnsnames.ora文件

ORCL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.10)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcl)
)
)
ORCLDG =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.56.20)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcldg)
)
)复制

9、RMAN复制数据库到备库，进行同步

备库操作，启动实例至nomount状态

[oracle@oracle dbs]$ cd ~
[oracle@oracle ~]$ echo $ORACLE_SID
orcldg
[oracle@oracle ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Fri Jan 11 15:52:21 2019
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to an idle instance.
SQL> create spfile from pfile;
File created.
SQL> startup nomount;
ORACLE instance started.
Total System Global Area 313159680 bytes
Fixed Size 2252824 bytes
Variable Size 222302184 bytes
Database Buffers 83886080 bytes
Redo Buffers 4718592 bytes复制

使用tnsping测试orcl及orcldg是否可达

rman target sys/oracle@orcl auxiliary sys/oracle@orcldg

复制数据库到备库，默认按如下执行没有并行，

duplicate target database for standby from active database nofilenamecheck;

如果需要打开并行多通道，需要按如下执行

run 
{
allocate channel d1 type disk;
allocate channel d2 type disk;
allocate channel d3 type disk;
allocate channel d4 type disk;
allocate auxiliary channel c1 type disk;
allocate auxiliary channel c2 type disk;
allocate auxiliary channel c3 type disk;
allocate auxiliary channel c4 type disk;
duplicate target database for standby from active database nofilenamecheck;
}复制

以下是不开关行的输出

[oracle@oracle admin]$ rman target sys/oracle@orcl auxiliary sys/oracle@orcldg
Recovery Manager: Release 11.2.0.4.0 - Production on Fri Jan 11 17:08:33 2019
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
connected to target database: ORCL (DBID=1525049921)
connected to auxiliary database: ORCL (not mounted)
RMAN> duplicate target database for standby from active database nofilenamecheck;
Starting Duplicate Db at 11-JAN-19
using target database control file instead of recovery catalog
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=19 device type=DISK
contents of Memory Script:
{
backup as copy reuse
targetfile '/u01/app/oracle/product/11.2.0/dbhome_1/dbs/orapworcl1' auxiliary format
'/u01/app/oracle/product/11.2.0/db_1/dbs/orapworcldg' ;
}
executing Memory Script
Starting backup at 11-JAN-19
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=73 instance=orcl1 device type=DISK
Finished backup at 11-JAN-19
contents of Memory Script:
{
backup as copy current controlfile for standby auxiliary format '/u01/app/oracle/oradata/orcldg/controlfile/control01.ctl';
restore clone controlfile to '/u01/app/oracle/oradata/orcldg/controlfile/control02.ctl' from
'/u01/app/oracle/oradata/orcldg/controlfile/control01.ctl';
}
executing Memory Script
Starting backup at 11-JAN-19
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile copy
copying standby control file
output file name=/u01/app/oracle/product/11.2.0/dbhome_1/dbs/snapcf_orcl1.f tag=TAG20190111T170841 RECID=2 STAMP=997290522
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:01
Finished backup at 11-JAN-19
Starting restore at 11-JAN-19
using channel ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: copied control file copy
Finished restore at 11-JAN-19
contents of Memory Script:
{
sql clone 'alter database mount standby database';
}
executing Memory Script
sql statement: alter database mount standby database
contents of Memory Script:
{
set newname for tempfile 1 to
"/u01/app/oracle/oradata/orcldg/tempfile/temp.266.997269191";
switch clone tempfile all;
set newname for datafile 1 to
"/u01/app/oracle/oradata/orcldg/datafile/system.256.997269101";
set newname for datafile 2 to
"/u01/app/oracle/oradata/orcldg/datafile/sysaux.257.997269101";
set newname for datafile 3 to
"/u01/app/oracle/oradata/orcldg/datafile/undotbs1.258.997269103";
set newname for datafile 4 to
"/u01/app/oracle/oradata/orcldg/datafile/users.259.997269103";
set newname for datafile 5 to
"/u01/app/oracle/oradata/orcldg/datafile/undotbs2.267.997269211";
set newname for datafile 6 to
"/u01/app/oracle/oradata/orcldg/datafile/hr.273.997270893";
backup as copy reuse
datafile 1 auxiliary format
"/u01/app/oracle/oradata/orcldg/datafile/system.256.997269101" datafile
2 auxiliary format
"/u01/app/oracle/oradata/orcldg/datafile/sysaux.257.997269101" datafile
3 auxiliary format
"/u01/app/oracle/oradata/orcldg/datafile/undotbs1.258.997269103" datafile
4 auxiliary format
"/u01/app/oracle/oradata/orcldg/datafile/users.259.997269103" datafile
5 auxiliary format
"/u01/app/oracle/oradata/orcldg/datafile/undotbs2.267.997269211" datafile
6 auxiliary format
"/u01/app/oracle/oradata/orcldg/datafile/hr.273.997270893" ;
sql 'alter system archive log current';
}
executing Memory Script
executing command: SET NEWNAME
renamed tempfile 1 to /u01/app/oracle/oradata/orcldg/tempfile/temp.266.997269191 in control file
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
Starting backup at 11-JAN-19
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile copy
input datafile file number=00001 name=+DATA/orcl/datafile/system.256.997269101
output file name=/u01/app/oracle/oradata/orcldg/datafile/system.256.997269101 tag=TAG20190111T170850
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:16
channel ORA_DISK_1: starting datafile copy
input datafile file number=00002 name=+DATA/orcl/datafile/sysaux.257.997269101
output file name=/u01/app/oracle/oradata/orcldg/datafile/sysaux.257.997269101 tag=TAG20190111T170850
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting datafile copy
input datafile file number=00006 name=+DATA/orcl/datafile/hr.273.997270893
output file name=/u01/app/oracle/oradata/orcldg/datafile/hr.273.997270893 tag=TAG20190111T170850
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:03
channel ORA_DISK_1: starting datafile copy
input datafile file number=00003 name=+DATA/orcl/datafile/undotbs1.258.997269103
output file name=/u01/app/oracle/oradata/orcldg/datafile/undotbs1.258.997269103 tag=TAG20190111T170850
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting datafile copy
input datafile file number=00005 name=+DATA/orcl/datafile/undotbs2.267.997269211
output file name=/u01/app/oracle/oradata/orcldg/datafile/undotbs2.267.997269211 tag=TAG20190111T170850
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting datafile copy
input datafile file number=00004 name=+DATA/orcl/datafile/users.259.997269103
output file name=/u01/app/oracle/oradata/orcldg/datafile/users.259.997269103 tag=TAG20190111T170850
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:01
Finished backup at 11-JAN-19
sql statement: alter system archive log current
contents of Memory Script:
{
switch clone datafile all;
}
executing Memory Script
datafile 1 switched to datafile copy
input datafile copy RECID=2 STAMP=997290566 file name=/u01/app/oracle/oradata/orcldg/datafile/system.256.997269101
datafile 2 switched to datafile copy
input datafile copy RECID=3 STAMP=997290566 file name=/u01/app/oracle/oradata/orcldg/datafile/sysaux.257.997269101
datafile 3 switched to datafile copy
input datafile copy RECID=4 STAMP=997290566 file name=/u01/app/oracle/oradata/orcldg/datafile/undotbs1.258.997269103
datafile 4 switched to datafile copy
input datafile copy RECID=5 STAMP=997290566 file name=/u01/app/oracle/oradata/orcldg/datafile/users.259.997269103
datafile 5 switched to datafile copy
input datafile copy RECID=6 STAMP=997290566 file name=/u01/app/oracle/oradata/orcldg/datafile/undotbs2.267.997269211
datafile 6 switched to datafile copy
input datafile copy RECID=7 STAMP=997290566 file name=/u01/app/oracle/oradata/orcldg/datafile/hr.273.997270893
Finished Duplicate Db at 11-JAN-19
RMAN>复制

恢复完结果

---查看备库情况
select DBID,NAME,OPEN_MODE,DATABASE_ROLE from v$database;
--mount模式启动同步（非ADG）
alter database recover managed standby database disconnect from session;复制

10、同步验证

使用scott用户创建表测试，登录备库查看，同时观察告警日志跟踪

例如create table dept2023 as select * from dept;

11、同步管理

停止同步进程
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
主备库延时同步
--先停止同步
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
--启动延迟同步
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DELAY 30 DISCONNECT FROM SESSION;
使用LGWR同步（ADG实时）
--如果MOUNT模式，要先open
alter database open
alter database recover managed standby database using current logfile disconnect from session;复制

12、同步验证日志查看

在主库上进行日志切换

ALTER SESSION SET nls_date_format='DD-MON-YYYY HH24:MI:SS';
SELECT sequence#, first_time, next_time FROM v$archived_log ORDER BY sequence#;
ALTER SYSTEM SWITCH LOGFILE;复制

在从库上执行如下语句查看日志是否同步切换到最新。

ALTER SESSION SET nls_date_format='DD-MON-YYYY HH24:MI:SS';
SELECT sequence#, first_time, next_time, applied FROM v$archived_log ORDER BY sequence#;复制

查看切换状态，是否有GAP或目标不可达的情况发生

select switchover_status from v$database;复制

如果返回to standby或session active表示无问题。

13、多种模式切换

查看当前保护模式

SELECT protection_mode FROM v$database;

多种模式如何切换

-- Maximum Availability.
ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='SERVICE=orcldg AFFIRM SYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCLDG';
ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE AVAILABILITY;
-- Maximum Performance.
ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='SERVICE=orcldg NOAFFIRM ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCLDG';
ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PERFORMANCE;
-- Maximum Protection.
ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='SERVICE=orcldg AFFIRM SYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCLDG';
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PROTECTION;
ALTER DATABASE OPEN;复制

14、主备切换

a)在主库检查切换

select switchover_status from v$database;

如果该列值为"TO STANDBY"则表示primary 数据库支持转换为standby 角色，否则的话你就需要重新检查一下Data Guard 配置，比如看看LOG_ARCHIVE_DEST_n 之类参数值是否正确有效等等。

b)主库切换成备库并关闭

CONNECT / AS SYSDBA
ALTER DATABASE COMMIT TO SWITCHOVER TO STANDBY;复制

建议直接执行下面这个，上面的有可能会话关不掉

ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;复制

关闭数据库

SHUTDOWN IMMEDIATE;复制

c)备库切换成主库

在备库上执行

CONNECT / AS SYSDBA
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY;复制

建议直接执行下面这个

ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;
SHUTDOWN IMMEDIATE;复制

再次打开变成主库

STARTUP;复制

d)原来的主库以备库方式启动

STARTUP NOMOUNT;
ALTER DATABASE MOUNT STANDBY DATABASE;
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;复制

15、强制切换（会丢数据，极端环境操作）

当主库不可用时，从库可以被激活成主库使用，需要在从库上执行如下SQL语句。打开从库使用。

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH;
ALTER DATABASE ACTIVATE STANDBY DATABASE;
ALTER DATABASE OPEN;复制

16、快照数据库

在Dataguard中，可以将standby备库切换为snapshot快照数据库，在切换为snapshot数据库后，备库将置于可读写的模式。可用于模拟业务功能测试。在使用完成之后，可以将快照数据库切换为物理备库。在此期间，备库可以接受主库传输过来的日志，但是不能应用日志，需要处于物理备库的时候才可以应用。

16.1将物理备库切换为快照数据库

1.备库配置快速恢复区

alter system set db_recovery_file_dest_size=10g;
alter system set db_recovery_file_dest='/u01/app/oracle/fast_recover_area';复制

2.备库关闭redo apply应用

--在关闭之前，备库的开启状态为：READ ONLY WITH APPLY

--关闭redo apply后，备库的开启状态为：READ ONLY

alter database recover managed standby database cancel;复制

3.切换为快照数据库

--执行转换为快照数据库后，备库的开启状态为：MOUNTED

alter database convert to snapshot standby;复制

--开启备库后，数据库开启状态为：READ WRITE

alter database open;复制

查看状态：

SQL> select open_mode,database_role,protection_mode,protection_level from v$database;
OPEN_MODE DATABASE_ROLE PROTECTION_MODE PROTECTION_LEVEL
-------------------- ---------------- -------------------- --------------------
READ WRITE SNAPSHOT STANDBY MAXIMUM AVAILABILITY MAXIMUM AVAILABILITY复制

在快照数据库上进行读写操作,此时不仅可以读，还可以写入数据

SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
SQL> insert into scott.dept values(50,'SECADMIN','CHINA');
1 row created.
SQL> commit;
Commit complete.
SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
50 SECADMIN CHINA复制

16.2将快照数据库切回物理备库

1.关闭备库，将备库启动到mount状态

shutdown immediate
start mount复制

2.执行切回命令

alter database convert to physical standby;复制

3.再次关闭备库，启动到open状态，开启实时应用

--关闭备库

shutdown immediate复制

--启动数据库到open状态

startup复制

--开始备库实时应用

alter database recover managed standby database using current logfile disconnect;复制

4.查看备库状态

SQL> select name,open_mode,database_role,protection_mode from v$database;
NAME OPEN_MODE DATABASE_ROLE PROTECTION_MODE
--------- -------------------- ---------------- --------------------
ADGDB READ ONLY WITH APPLY PHYSICAL STANDBY MAXIMUM AVAILABILITY复制

5.这个时候，再回去查看scott表信息，发现处于snapshot数据库时insert的数据已经不存在

SQL> select * from scott.dept;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON复制

17、实施注意事项！！

主库和备库时间建议要一致，稳妥的情况是一定要部署NTP同步。
主库RAC的两个节点都需要修改tnsnames.ora以保证传归档及redo可达
密码文件要一致，sys的密码要一致，最好校验一下密码文件的MD5值，确认一模一样，如果主库修改了一定要及时更新密码文件及密码
主备库环境变量，一定要仔细核对，ORACLE_BASE与ORACLE_HOME别有出错，例如oracle_base的值最后加/，设定ORACLE_HOME变量时又引用ORACLE_BASE多加个/，会引起启动的实例监听无法连接。

也欢迎关注我的公众号【徐sir的IT之路】，一起学习！
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最后修改时间：2023-12-25 22:36:14

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数据库日常（共29篇）

各种数据库日常

修定记录
- 0、测试环境信息
- 1、主库归档开启
- 2、主库force logging模式开启
- 3、主库创建standby redo log 文件
- 4、备库创建目录
- 5、参数修改
- 6、创建备库参数文件及口令文件
- 7、主库监听相关创建
- 8、备库监听相关创建
- 9、RMAN复制数据库到备库，进行同步
- 10、同步验证
- 11、同步管理
- 12、同步验证日志查看
- 13、多种模式切换
- 14、主备切换
- 15、强制切换（会丢数据，极端环境操作）
- 16、快照数据库
- 17、实施注意事项！！
  - 16.1将物理备库切换为快照数据库
  - 16.2将快照数据库切回物理备库