一、准备工作
- 环境准备
- 主数据库Oracle Database安装
- 备服务器Oracle Database software 安装
二、正式配置
三、基本管理
--------------------------------------------------------------分割线-------------------------------------------------------------
一、准备工作
1.环境配置:
主机配置
节点 | 操作系统 | 主机名称 | IP地址 |
主库 | CentOS6.4_x86_64 | dgp | 192.168.10.61 |
备库 | CentOS6.4_x86_64 | dgs | 192.168.10.62 |
修改主机名:
[root@db /]# cat /etc/sysconfig/network[root@db /]# sed -i s/HOSTNAME=.*/HOSTNAME=dgp/ /etc/sysconfig/network[root@db /]# reboot
规划数据库配置
节点 | Oracle版本 | SID | db_name |
db_unique_name |
主库 | 11.2.0.4 | orcl | orcl | orcl |
备库 | 11.2.0.4 | orcl | orcl | orcl_std |
以上完成之后,对两台主机进行以下操作:
1)禁用防火墙
[root@dgp ~]# chkconfig iptables off [root@dgp ~]# service iptables stop
2)禁用selinux
[root@dgp ~]# sed -i s/SELINUX=.*/SELINUX=disabled/ /etc/sysconfig/selinux[root@dgp ~]# setenforce 0
3)配置host文件
[root@dgp ~]# cat /etc/hosts[root@dgp ~]# echo -e '192.168.10.61 dgp \n192.168.10.62 dgs' >>/etc/hosts
备注:echo -e 表示开启转义。
4)软件准备
数据库文件如下:
p13390677_112040_Linux-x86-64_1of7.zip
p13390677_112040_Linux-x86-64_2of7.zip
创建路径 /install路径,上传安装文件并解压。
[root@dgp /]# mkdir /install[root@dgp /]# cd /install[root@dgp /]# unzip p13390677_112040_Linux-x86-64_1of7.zip[root@dgp /]# unzip p13390677_112040_Linux-x86-64_1of7.zip
2.主数据库Oracle Database安装
配置最小参数
修改参数文件/etc/sysctl.conf
[root@dgp /]# echo 'fs.suid_dumpable = 1 fs.aio-max-nr = 1048576 fs.file-max = 6815744 kernel.shmall = 2097152 kernel.shmmax = 536870912 kernel.shmmni = 4096 # semaphores: semmsl, semmns, semopm, semmni kernel.sem = 250 32000 100 128 net.ipv4.ip_local_port_range = 9000 65500 net.core.rmem_default=262144 net.core.rmem_max=4194304 net.core.wmem_default=262144 net.core.wmem_max=1048586' >> /etc/sysctl.conf
执行命令使配置生效
[root@dgp /]# /sbin/sysctl -p
修改limits.conf
添加以下内容到配置文件/etc/security/limits.conf:
[root@db /]# echo 'oracle soft nproc 16384 oracle hard nproc 16384 oracle soft nofile 4096 oracle hard nofile 65536 oracle soft stack 10240' >> /etc/security/limits.conf
安装必要的rpm包
[root@dgp /]# yum install -y binutils-2*x86_64* glibc-2*x86_64* nss-softokn-freebl-3*x86_64* glibc-2*i686* nss-softokn-freebl-3*i686* compat-libstdc++-33*x86_64* yum install -y glibc-common-2*x86_64* glibc-devel-2*x86_64* glibc-devel-2*i686* glibc-headers-2*x86_64* elfutils-libelf-0*x86_64* yum install -y elfutils-libelf-devel-0*x86_64* gcc-4*x86_64* gcc-c++-4*x86_64* ksh-*x86_64* libaio-0*x86_64* yum install -y libaio-devel-0*x86_64* libaio-0*i686* libaio-devel-0*i686* libgcc-4*x86_64* libgcc-4*i686* libstdc++-4*x86_64* libstdc++-4*i686* yum install -y libstdc++-devel-4*x86_64* make-3.81*x86_64* numactl-devel-2*x86_64* sysstat-9*x86_64* compat-libstdc++-33*i686* compat-libcap*
创建配置用户
[root@dgp /]# groupadd -g 501 oinstall groupadd -g 502 dba groupadd -g 503 oper groupadd -g 504 asmadmin groupadd -g 506 asmdba groupadd -g 505 asmoper useradd -u 502 -g oinstall -G dba,asmdba,oper oracle [root@dgp install]# passwd oracleChanging password for user oracle.New password: BAD PASSWORD: it is too simplistic/systematicRetype new password: passwd: all authentication tokens updated successfully.
修改"/etc/security/limits.d/90-nproc.conf" 文件中的内容
将 “* soft nproc 1024”这一行修改为“* - nproc 16384”
[root@dgp /]# cp /etc/security/limits.d/90-nproc.conf /etc/security/limits.d/90-nproc.conf_bak [root@dgp /]# sed -i s/.*1024/*\ -\ nproc\ 16384/ /etc/security/limits.d/90-nproc.conf
创建数据库安装路径
[root@dgp /]# mkdir -p /u01/app/oracle/product/11.2.0/db_1 chown -R oracle:oinstall /u01 chmod -R 775 /u01
登录oracle用户,并在 ".bash_profile" 文件尾部添加内容。
[root@dgp /]# su - oracle[oracle@dgp /]$ pwd[oracle@dgp /]$ cat >> .bash_profile <<'EOF'#Oracle Settings TMP=/tmp; export TMP TMPDIR=$TMP; export TMPDIR ORACLE_HOSTNAME=dgp; export ORACLE_HOSTNAME ORACLE_UNQNAME=orcl; export ORACLE_UNQNAME ORACLE_BASE=/u01/app/oracle; export ORACLE_BASE ORACLE_HOME=$ORACLE_BASE/product/11.2.0/db_1; export ORACLE_HOME ORACLE_SID=orcl; export ORACLE_SID PATH=/usr/sbin:$PATH; export PATH PATH=$ORACLE_HOME/bin:$PATH; export PATH LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib; export LD_LIBRARY_PATH CLASSPATH=$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib; export CLASSPATHEOF
备注:配置备库时候:ORACLE_HOSTNAME=dgs ORACLE_UNQNAME=orcl_std ORACLE_SID=orcl
安装数据库
直接以Oracle用户登录,执行安装
[oracle@dgp /]$ cd /install/database、[oracle@dgp /]$ ll[oracle@dgp /]$ ./runInstaller
图形界面忽略,过程中在root用户下执行脚本。
[root@dgp ~]# /u01/app/oraInventory/orainstRoot.sh [root@dgp ~]# /u01/app/oracle/product/11.2.0/db_1/root.sh
备注:主库选择安装数据库软件和数据库实例,备库仅安装数据库软件。
设置Oracle Database自启动
修改/etc/oratab配置文件中每一个重起标志设置成Y:
[root@dgp /]# sed -i 's/\(orcl:\)\(.*:\)N/\1\2Y/' /etc/oratab
创建自启动配置文件/etc/init.d/dbora:
[root@dgp /]# cat >> /etc/init.d/dbora <<EOF#!/bin/sh# chkconfig: 345 99 10# description: Oracle auto start-stop script.ORA_HOME=/u01/app/oracle/product/11.2.0/db_1ORA_OWNER=oracleif [ ! -f $ORA_HOME/bin/dbstart ]thenecho "Oracle startup: cannot start"exitficase "$1" in'start')# Start the Oracle databases:# The following command assumes that the oracle login# will not prompt the user for any valuessu - $ORA_OWNER -c "$ORA_HOME/bin/dbstart $ORA_HOME"touch /var/lock/subsys/dbora;;'stop')# Stop the Oracle databases:# The following command assumes that the oracle login# will not prompt the user for any valuessu - $ORA_OWNER -c "$ORA_HOME/bin/dbshut $ORA_HOME"rm -f /var/lock/subsys/dbora;;esacEOF
赋予执行权限,添加自启动
[root@dgp ~]# chmod 750 /etc/init.d/dbora chkconfig --add dbora chkconfig dbora on
3.备服务器Oracle Database software 安装
备服务器安装software,过程参考主库数据库安装过程。
二、正式配置
5,开始搭建配置ADG
1)主库检查归档模式等:
在主库操作:#查看log_mode、force_logging、flashback_onSQL> select name,log_mode,force_logging,flashback_on from v$database; #切换成归档模式SQL> SHUTDOWN IMMEDIATE;SQL> STARTUP MOUNT;SQL> ALTER DATABASE ARCHIVELOG; #修改成归档模式#开启FORCE LOGGINGSQL> ALTER DATABASE FORCE LOGGING #开启FORCE LOGGING
#修改归档日志路径(按需修改,这里仅仅列出供参考)#[oracle@dgp /]$ mkdir /u01/app/oracle/archivelog#SQL> archive log list#SQL> alter system set log_archive_dest_1='location=/u01/app/oracle/archivelog'; SQL> alter database flashback on; #开启flashback onSQL> ALTER DATABASE OPEN;
2)主库添加SRL:
注意:standby redo log比 redo log 多一个,并且大小保持一致。SQL> select * from v$log;SQL> select * from v$logfile;SQL> alter database add standby logfile group 11 '/u01/app/oracle/oradata/orcl/redo_std01.log' size 50M;SQL> alter database add standby logfile group 12 '/u01/app/oracle/oradata/orcl/redo_std02.log' size 50M;SQL> alter database add standby logfile group 13 '/u01/app/oracle/oradata/orcl/redo_std03.log' size 50M;SQL> alter database add standby logfile group 14 '/u01/app/oracle/oradata/orcl/redo_std04.log' size 50M;
3)主库修改参数:
#修改参数(可以用sql命令修改,也可以直接修改pfile文件)[oracle@dgp /]$ sqlplus / as sysdbaSQL > alter system set log_archive_config='DG_CONFIG=(orcl,orcl_std)' scope=both;alter system set log_archive_dest_1='LOCATION=USE_DB_RECOVERY_FILE_DEST VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=orcl' scope=both; #主库log路径 alter system set log_archive_dest_2='SERVICE=orcl_std LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=orcl_std' scope=both; #备库log路径 alter system set log_archive_dest_state_1='enable' scope=both; alter system set log_archive_dest_state_2='enable' scope=both; # alter system set db_file_name_convert='/u01/oracle/datafile','/u01/oracle/datafile' scope=both; #主备路径一致,忽略 # alter system set log_file_name_convert='/u01/oracle/onlinelog','/u01/oracle/onlinelog' scope=both; #主备路径一致,忽略 alter system set fal_server='orcl_std' scope=both; alter system set fal_client='orcl' scope=both; alter system set standby_file_management='AUTO' scope=both;alter system set db_unique_name='orcl' scope=both;#检查主库pfile文件initorcl.ora[oracle@dgp /]$ cat /u01/app/oracle/product/11.2.0/db_1/dbs/initorcl.oraorcl.__db_cache_size=687865856orcl.__java_pool_size=16777216orcl.__large_pool_size=33554432orcl.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environmentorcl.__pga_aggregate_target=671088640orcl.__sga_target=989855744orcl.__shared_io_pool_size=0orcl.__shared_pool_size=234881024orcl.__streams_pool_size=0*.audit_file_dest='/u01/app/oracle/admin/orcl/adump'*.audit_trail='db'*.compatible='11.2.0.4.0'*.control_files='/u01/app/oracle/oradata/orcl/control01.ctl','/u01/app/oracle/fast_recovery_area/orcl/control02.ctl'*.db_block_size=8192*.db_domain=''*.db_name='orcl'*.db_recovery_file_dest='/u01/app/oracle/fast_recovery_area'*.db_recovery_file_dest_size=4385144832*.diagnostic_dest='/u01/app/oracle'*.dispatchers='(PROTOCOL=TCP) (SERVICE=orclXDB)'*.fal_client='orcl'*.fal_server='orcl_std'*.log_archive_dest_1='location=USE_DB_RECOVERY_FILE_DEST valid_for=(all_logfiles,all_roles) db_unique_name=orcl'*.log_archive_dest_2='SERVICE=orcl_std LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=orcl_std'*.log_archive_dest_state_1='enable'*.log_archive_dest_state_2='enable'*.memory_target=1660944384*.open_cursors=300*.processes=150*.remote_login_passwordfile='EXCLUSIVE'*.standby_file_management='AUTO'*.undo_tablespace='UNDOTBS1'*.db_unique_name='orcl'*.log_archive_config='DG_CONFIG=(orcl,orcl_std)'检查完成确认无误后,重启数据库 SQL> shutdown immediateSQL> start nomountSQL> create spfile from pfile='/u01/app/oracle/product/11.2.0/db_1/dbs/initorcl.ora'; #以pfile创建新的spfile SQL> startupSQL> show parameter spfile #确认以spfile启动备注:备库的pfile、control file将安排和rman备份完成后创建,然后和其他文件一起copy至备库。
4)主库配listener.ora和tnsname.ora
(1)主库listener.ora配置:[oracle@dgp admin]$ cat /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora# listener.ora Network Configuration File: /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora# Generated by Oracle configuration tools.SID_LIST_LISTENER =(SID_LIST = (SID_DESC = (GLOBAL_DBNAME = orcl) (SID_NAME = orcl) ))LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = dgp)(PORT = 1521)) (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521)) ) )ADR_BASE_LISTENER = /u01/app/oracle
(2)主库tnsnames.ora配置:[oracle@dgp admin]$ cat /u01/app/oracle/product/11.2.0/db_1/network/admin/tnsnames.ora # tnsnames.ora Network Configuration File: /u01/app/oracle/product/11.2.0/db_1/network/admin/tnsnames.ora# Generated by Oracle configuration tools.ORCL = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = dgp)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl) ) )ORCL_STD = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = dgs)(PORT = 1521)) ) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl_std) ) )
(2)主库监听测试:# [oracle@dgp ~]$ lsnrctl reload[oracle@dgp ~]$ lsnrctl stop[oracle@dgp ~]$ lsnrctl start[oracle@dgp ~]$ lsnrctl status[oracle@dgp ~]$ sqlplus system/****@orcl #测试是否正常
至此主库的配置结束,下面将为备库准备相关文件。
5)RMAN备份主库
#在主库操作[oracle@dgp ~]$ rman target /RMAN> backup database plus archivelog#备注:注意一下rman输出内容中的备份文件路径#备用命令: backup current controlfile for standby format '/XXX/dbbackup/CTL_%U'; backup database format '/XXX/dbbackup/DB_%d_%U' PLUS ARCHIVELOG;
6)创建备库pfile文件initorcl_std.ora
#在主库操作[oracle@dgp ~]$ cd /u01/app/oracle/product/11.2.0/db_1/dbs[oracle@dgp ~]$ cp initorcl.ora initorcl_std.ora#修改initorcl_std.ora中内容,修改后的内容见下面新的initorcl_std.ora#红色为DG相关参数,红色绿底为修改过的内容[oracle@dgp ~]$ cat initorcl_std.oraorcl.__db_cache_size=687865856orcl.__java_pool_size=16777216orcl.__large_pool_size=33554432orcl.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environmentorcl.__pga_aggregate_target=671088640orcl.__sga_target=989855744orcl.__shared_io_pool_size=0orcl.__shared_pool_size=234881024orcl.__streams_pool_size=0*.audit_file_dest='/u01/app/oracle/admin/orcl/adump'*.audit_trail='db'*.compatible='11.2.0.4.0'*.control_files='/u01/app/oracle/oradata/orcl/control01.ctl','/u01/app/oracle/fast_recovery_area/orcl/control02.ctl'*.db_block_size=8192*.db_domain=''*.db_name='orcl'*.db_recovery_file_dest='/u01/app/oracle/fast_recovery_area'*.db_recovery_file_dest_size=4385144832*.diagnostic_dest='/u01/app/oracle'*.dispatchers='(PROTOCOL=TCP) (SERVICE=orclXDB)'*.fal_client='orcl_std'*.fal_server='orcl'*.log_archive_dest_1='location=USE_DB_RECOVERY_FILE_DEST valid_for=(all_logfiles,all_roles) db_unique_name=orcl_std'*.log_archive_dest_2='SERVICE=orcl LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=orcl'*.log_archive_dest_state_1='enable'*.log_archive_dest_state_2='enable'*.memory_target=1660944384*.open_cursors=300*.processes=150*.remote_login_passwordfile='EXCLUSIVE'*.standby_file_management='AUTO'*.undo_tablespace='UNDOTBS1'*.db_unique_name='orcl_std'*.log_archive_config='DG_CONFIG=(orcl,orcl_std)'
6)创建备库控制文件
#在主库操作 [oracle@dgp ~]$ sqlplus / as sysdba SQL> ALTER DATABASE CREATE STANDBY CONTROLFILE AS '/u01/app/oracle/fast_recovery_area/ORCL/backupset/orcl_stby.ctl'
7)传输文件至备库
需要copy至备库的文件有:rman备份、备库pfile、备库controlfile、listener.ora、tnsnames.ora、密码文件。
在备库上创建必要目录
在备库操作:[root@dgs ~]# su - oracle[oracle@dgs ~]$ mkdir /u01/app/oracle/oradata/orcl/[oracle@dgs ~]$ mkdir /u01/app/oracle/fast_recovery_area/orcl/[oracle@dgs ~]$ mkdir /u01/app/oracle/admin/orcl/adump[oracle@dgs ~]$ mkdir /u01/app/oracle/fast_recovery_area/ORCL/#[oracle@dgs ~]$ mkdir /u01/app/oracle/archivelog #忽略
在主库操作:#配置主库oracle用户免密登录备库主机oracle用户[oracle@dgp dbs]$ ssh-keygen #一直按回车[oracle@dgp dbs]$ ssh-copy-id -i .ssh/id_rsa.pub oracle@dgs #输入备库oracle操作系统用户密码#开始copy至备库[oracle@dgp ~]$ scp -r /u01/app/oracle/fast_recovery_area/ORCL/backupset oracle@dgs:/u01/app/oracle/fast_recovery_area/ORCL/ #controlfile 和 RMAN备份[oracle@dgp ~]$ scp /u01/app/oracle/product/11.2.0/db_1/dbs/initorcl_std.ora oracle@dgs:/u01/app/oracle/product/11.2.0/db_1/dbs #pfile文件initorcl_std.ora[oracle@dgp ~]$ scp /u01/app/oracle/product/11.2.0/db_1/dbs/orapworcl oracle@dgs:/u01/app/oracle/product/11.2.0/db_1/dbs/ #密码文件orapworcl[oracle@dgp ~]$ scp /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora oracle@dgs:/u01/app/oracle/product/11.2.0/db_1/network/admin #listener.ora[oracle@dgp ~]$ scp /u01/app/oracle/product/11.2.0/db_1/network/admin/tnsnames.ora oracle@dgs:/u01/app/oracle/product/11.2.0/db_1/network/admin #tnsnames.ora#复制备库控制文件至initorcl_std.ora指定位置(还是在主库操作,这里在主库ssh远程登录执行命令,避免切换窗口)[oracle@dgp oracle]$ ssh oracle@dgs cp /u01/app/oracle/fast_recovery_area/ORCL/backupset/orcl_stby.ctl /u01/app/oracle/oradata/orcl/control01.ctl[oracle@dgp oracle]$ ssh oracle@dgs cp /u01/app/oracle/fast_recovery_area/ORCL/backupset/orcl_stby.ctl /u01/app/oracle/fast_recovery_area/orcl/control02.ctl
至此,除listener.ora有待修改,备库的相关文件准备完成,下面将进入最后配置阶段。
8)备库配置监听
备库操作:(1)修改监听件listener.ora修改后查看,其他红色为修改的内容。#注意:备库的SID_NAME为orcl,因此备库listener.ora静态监听SID_LIST_LISTENER中的配置SID_NAME = orcl,不能设为orcl_std,orcl_std是db_unique_name。[oracle@dgs admin]$ cat /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora # listener.ora Network Configuration File: /u01/app/oracle/product/11.2.0/db_1/network/admin/listener.ora# Generated by Oracle configuration tools.SID_LIST_LISTENER =(SID_LIST = (SID_DESC = (GLOBAL_DBNAME = orcl_std) (SID_NAME = orcl) ))LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = dgs)(PORT = 1521)) (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521)) ) )ADR_BASE_LISTENER = /u01/app/oracle(2)备库的tnsnames.ora和主库一样,无需修改(3)重启监听并验证 在备库: [oracle@dgs ~]$ lsnrctl stop [oracle@dgs ~]$ lsnrctl start [oracle@dgs ~]$ lsnrctl status [oracle@dgs ~]$ sqlplus sys/******@orcl as sysdba #在备库上登录主库 [oracle@dgs ~]$ sqlplus sys/******@orcl_std as sysdba #在备库上登录备库 在主库: [oracle@dgs ~]$ sqlplus sys/******@orcl as sysdba #在主库上登录主库 [oracle@dgs ~]$ sqlplus sys/******@orcl_std as sysdba #在备库上登录备库
9)还原备库
#确认一下,至此备库相关文件均已修改完成。备库RMAN恢复[oracle@dgs oracle]$ export ORACLE_SID=orcl[oracle@dgs oracle]$ sqlplus / as sysdbaSQL> create spfile from pfile='/u01/app/oracle/product/11.2.0/db_1/dbs/initorcl_std.ora'; #创建备库spfileSQL> startup mount;SQL> show paramter spfile; #确认以spfile启动SQL> exit[oracle@dgs oracle]$ rman target /RMAN> alter database mount; #或者alter database mount standby database;RMAN> restore database;RMAN> recover database;
10)开启同步并验证
# 此时主库数据库处于open状态,备库处于mount状态
(1)开启同步:在备库操作SQL> alter database open read only;SQL> alter database recover managed standby database using current logfile disconnect from session;(2)验证在主库操作SQL> create user mydb identified by ******;SQL> alter system switch logfile;在备库操作SQL> select username from dba_users where name='MYDB'
查看备库应用状态SQL> select thread#,sequence#,standby_dest,archived,applied,status from v$archived_log;
三、基本管理
1.检查状态查看数据库状态select open_mode,protection_mode,database_role,switchover_status from v$database;select max(sequence#) from v$log;--检查两边的序列好,是否一致 主库切换日志,alert system switch logfile;查看备库应用状态select thread#,sequence#,standby_dest,archived,applied,status from v$archived_log;查看有没有GAPselect * from v$archive_dest_status where dest_id=2;select status,gap_status from v$archive_dest_status where dest_id=2;备库查看RFS接收日志和MRP应用日志同步主库情况select process, sequence#,GROUP#,thread#,status,delay_mins from v$managed_standby; #备库查询其中,其中ARCH是归档进程,RFS是归档传输进程,MRP0是日志应用进程备库查看日志应用进度及数据库模式select dbid,name,open_mode,current_scn,protection_mode,database_role,force_logging,open_mode,switchover_status from v$database;
2.启动数据库: --先启备库 sql>startup nomount sql>alter database mount standby database; sql>alter database open; #或者alter database open read only; sql>alter database recover managed standby database using current logfile disconnect from session; --再启主库 sql>startup 3.关闭数据库--先关主库: sql>shutdown immediate --再关备用库: sql>alter database recover managed standby database cancel; --停止同步 sql>shutdown immediate;4.主备切换待续。。。。。。
来源:https://www.cnblogs.com/skyan/p/12313312.html