Oracle RAC 日常管理
更多精彩内容尽在www.leonarding.com一RAC环境
RAC架构，2节点信息
节点1
SQL> show parameter instance
NAME TYPE VALUE
------------------------------------ ----------- -----------------------------------------------
active_instance_count integer
cluster_database_instances integer 2
instance_groups string
instance_name string RACDB1
instance_number Integer 1
instance_type string RDBMS
open_links_per_instance integer 4
parallel_instance_group string
parallel_server_instances integer 2
节点2
SQL> show parameter instance
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
active_instance_count integer
cluster_database_instances integer 2
instance_groups string
instance_name string RACDB2
instance_number integer 2
instance_type string RDBMS
open_links_per_instance integer 4
parallel_instance_group string
parallel_server_instances integer 2
数据库版本
SQL> select * from v$version;
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
操作系统信息
节点1
$ uname -a
Linux rac1 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:02 EDT 2007 i686 i686 i386 GNU/Linux
节点2
$ uname -a
Linux rac2 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:02 EDT 2007 i686 i686 i386 GNU/Linux
$ uname -a
Linux leonarding1.oracle.com 2.6.32-200.13.1.el5uek #1 SMP Wed Jul 27 21:02:33 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
RAC所有资源信息
$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application ONLINE ONLINE rac1
ora....B2.inst application ONLINE ONLINE rac2
ora....DB1.srv application ONLINE ONLINE rac2
ora.....TAF.cs application ONLINE ONLINE rac2
ora.RACDB.db application ONLINE ONLINE rac2
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
二演示启动和关闭crs主进程
（1）简单说说RAC日常管理都有哪些内容
1.节点管理：node日常管理
2.网络管理：例如网卡配置 VIP虚拟ip 外部网络内部网络
3.集群管理：CRS 集群资源管理 OCR oracle集群注册表 srv 服务管理 votedisk表决磁盘
4.应用管理：数据库、实例、监听器、虚拟ip、注册到RAC中的各种资源
（2）RAC集群守护进程
$ pwd
/etc/init.d
$ ll | grep init*
init.crsd:# init.crsd - Control script for the CRS daemon.
init.crsd:# only be invoked from init.crs or from inittab.
init.crsd:# No manual invocation of init.crsd is supported.
init.crsd:# or on an automatic startup, this file will exist. init.crsd run will
init.cssd:# directory. It should only be invoked from init.crs.
init.evmd:# be invoked from init.crs.
$ ls init*
init.crsinit.crsdinit.cssdinit.evmd
这些就是RAC集群守护进程，存放在Linux开机启动的脚本目录下，可以随操作系统的启动而启动。
./init.crsstart 启动集群进程
./init.crsstop 停止集群进程
./init.crsenable 随操作系统的启动而启动
./init.crsdisable 不随操作系统的启动而启动
注：init.crs 脚本是init.crsdinit.cssdinit.evmd脚本的引导脚本
crs主要进程
(1)crsd
负责管理HA 高可靠性操作
管理crs资源，如linstener，vip，ons，gsn等
由root用户管理、启动
(2)ocssd
管理各节点的关系，用于节点间通信
由oracle用户运行管理
(3)oprocd
集群进程管理 —Process monitor for the cluster.集群监控进程
仅在没有使用vendor的集群软件状态下运行
(4)evmd
事件检测进程，由oracle用户运行管理
(5)主要log位置
$ORA_CRS_HOME/log/节点主机名(rac1rac2)/racg 节点日志
$ORA_CRS_HOME/log/节点主机名(rac1rac2)/crsd 集群软件日志
$ORA_CRS_HOME/crs/init
$ORA_CRS_HOME/css/log 节点间通信的日志
$ORA_CRS_HOME/css/init
$ORA_CRS_HOME/evm/log 事件监控日志
$ORA_CRS_HOME/evm/init
$ORA_CRS_HOME/srvm/log
演示
$ su – root 必须使用root用户执行RAC集群脚本
Password:
# cd /etc/init.d
# ./init.crsdisable
Automatic startup disabled for system boot.
# ./init.crsenable
Automatic startup enabled for system boot.
# ./init.crsstop 停止CRS主进程
Shutting down Oracle Cluster Ready Services (CRS):
Stopping resources.
Successfully stopped CRS resources 包含crsd
Stopping CSSD.
Shutting down CSS daemon. 包含cssd
Shutdown request successfully issued.
Shutdown has begun. The daemons should exit soon.
# ./init.crs start 启动CRS主进程
Startup will be queued to init within 90 seconds. 启动将会在90秒内完成
# crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application ONLINE ONLINE rac1
ora....B2.inst application ONLINE ONLINE rac2
ora....DB1.srv application ONLINE ONLINE rac2
ora.....TAF.cs application ONLINE ONLINE rac2
ora.RACDB.db application ONLINE ONLINE rac2
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
等待一会并不一定是90秒，CRS集群资源全部启动了
（3）RAC集群命令集目录
$ORACLE_HOME/crs_1/bin
所有集群命令都放在这个目录下
（4）节点层命令
$ olsnodes -n
rac1 1
rac2 2
$ olsnodes -n -p
rac1 1 rac1-priv
rac2 2 rac2-priv
$ olsnodes -n -p -i
rac1 1 rac1-priv rac1-vip
rac2 2 rac2-priv rac2-vip
这个命令用来显示集群节点的信息
参数解释：n 打印节点号
P 打印私有网络名
i 打印虚拟ip
（2）网络层命令
$ oifcfg Oracle网卡配置工具
Name:
oifcfg - Oracle Interface Configuration Tool.
Usage:oifcfg iflist [-p [-n]]
oifcfg setif {-node| -global} {/:}...
oifcfg getif [-node| -global] [ -if [/] [-type ] ]
oifcfg delif [-node| -global] [[/]]
oifcfg [-help]
- name of the host, as known to a communications network
- name by which the interface is configured in the system
- subnet address of the interface
- type of the interface { cluster_interconnect | public | storage }
$ oifcfg iflist 查看网卡对应的网段，oracle网卡配置工具
eth0192.168.1.0
eth1192.168.2.0
eth2192.168.61.0
$ oifcfg getif 没有配置之前是什么内容也没有
$ oifcfg setif -global eth0/192.168.1.0:public oracle网卡配置工具指定公有网卡
$ oifcfg setif -global eth1/192.168.2.0:cluster_interconnect oracle网卡配置工具指定私有网
$ oifcfg getif 获取配置结果
eth0192.168.1.0globalpublic eth0是全局公共网卡
eth1192.168.2.0globalcluster_interconnect eth1是全局私有网卡
三查看OCR磁盘的信息，并打印出OCR磁盘的内容
OCR：称为Oracle 集群注册表，一般RAC集群中至少有2个OCR磁盘互为镜像，OCR里面注册了集群中的所有资源信息（数据库实例监听器 VIP OCR磁盘表决磁盘服务节点应用网卡等）
我们可以使用ocrcheck命令检查OCR磁盘状态
节点1
RACDB1@rac1 /home/oracle$ ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 2
Total space (kbytes) : 104344 总空间
Used space (kbytes) : 4324 使用空间
Available space (kbytes) : 100020 剩余空间
ID : 1752469369
Device/File Name : /dev/raw/raw1 磁盘路径
Device/File integrity check succeeded
Device/File not configured
Cluster registry integrity check succeeded
节点2
RACDB2@rac2 /home/oracle$ ocrcheck
Status of Oracle Cluster Registry is as follows :
Version : 2
Total space (kbytes) : 104344
Used space (kbytes) : 4324
Available space (kbytes) : 100020
ID : 1752469369
Device/File Name : /dev/raw/raw1
Device/File integrity check succeeded
Device/File not configured
Cluster registry integrity check succeeded
使用ocrdump命令查看OCR内容，但这个命令不能用于OCR的备份恢复只可以用于阅读
RACDB1@rac1 /home/oracle$ ocrdump -stdout | more
UNDEF :
SECURITY : {USER_PERMISSION : PROCR_ALL_ACCESS, GROUP_PERMISSION : PROCR_READ, OTHER_PERMISSION : PROCR_READ, USER_NAME : root, GROUP_NAME : root}
ORATEXT : (ADDRESS=(PROTOCOL=ipc)(KEY=Arac1_crs_evm))
SECURITY : {USER_PERMISSION : PROCR_ALL_ACCESS, GROUP_PERMISSION : PROCR_READ, OTHER_PERMISSION : PROCR_READ, USER_NAME : root, GROUP_NAME : root}
ORATEXT : (ADDRESS=(PROTOCOL=ipc)(KEY=Arac2_crs_evm))
SECURITY : {USER_PERMISSION : PROCR_ALL_ACCESS, GROUP_PERMISSION : PROCR_READ, OTHER_PERMISSION : PROCR_READ, USER_NAME : root, GROUP_NAME : root}
使用ocrconfig命令配置维护OCR磁盘，例如导出备份OCRDUMP文件再导入来恢复OCR
$ su - root
Password:
# cd /home/oracle
# ll
total 4
drwxr-xr-x 3 oracle oinstall 4096 Jul52013 Desktop
# ocrconfig -export ocr_bk.dmp 导出OCR磁盘内容，一旦有问题可以导入恢复
# ll
total 104
drwxr-xr-x 3 oracle oinstall4096 Jul52013 Desktop
-rw-r--r-- 1 root root 97517 Jul4 17:57 ocr_bk.dmp
# strings ocr_bk.dmp 可以使用这个命令来查看dump文件内容
# ocrconfig -import ocr_bk.dmp 导入dump文件恢复OCR
# ocrconfig –replace ocrmirror /dev/raw/raw2创建新的OCR磁盘镜像
四查看voting disk磁盘信息
Voting Disk 这个文件主要用于记录节点成员状态，在出现脑裂时，决定那个Partion获得控制权，其他的Partion必须从集群中剔除。Voting disk使用的是一种“多数可用算法”，如果有多个Voting disk，，则必须一半以上的Votedisk同时存活，Clusterware才能正常使用。比如配置了4个Votedisk，坏一个Votedisk，集群可以正常工作，如果坏了2个，则不能满足半数以上，集群会立即宕掉，所有节点立即重启，所以如果添加Votedisk，尽量不要只添加一个，而应该添加2个,总共的数量保证为奇数。
（1）表决磁盘检查，必须为单数
RACDB2@rac2 /home/oracle$ crsctl query css votedisk
0. 0 /dev/raw/raw2
located 1 votedisk(s). 定位1个表决磁盘
（2）备份votedisk盘
因为我们的表决磁盘使用的是裸设备，因此使用裸设备的dd命令来备份表决磁盘，使用root用户
# dd if=/dev/raw/raw2 of=/home/oracle/voting_disk.bak
208864+0 records in 表决磁盘中的记录数
208864+0 records out
106938368 bytes (107 MB) copied, 104.614 seconds, 1.0 MB/s
# ll
total 104644
drwxr-xr-x 3 oracle oinstall 4096 Jul52013 Desktop
-rw-r--r-- 1 root root 97517 Jul4 17:57 ocr_bk.dmp
-rw-r--r-- 1 root root 106938368 Jul4 18:37voting_disk.bak
# du -sm voting_disk.bak 备份文件103MB
103 voting_disk.bak
（3）恢复votedisk盘
# dd if=/home/oracle/voting_disk.bak of=/dev/raw/raw2
使用上述命令即可恢复表决磁盘，由于我们的表决磁盘是正常状态，因此不做恢复演示
（4）通过strings命令查看votedisk内容
# strings voting_disk.bak |sort -u
fSLC
ssLckcoT
SslcLlik
sSlcrEp0
}|{z
五用srvctl分别启动ASM,数据库实例和数据库
srvctl是应用层命令，称作“服务管理工具”可以操作database；instance；listener；nodes；ASM；service；application
，其中application又包括“GSDONSVIP”，这些资源都可以通过srvctl工具统一管理。
演示
（1）关闭节点1的RAC实例
RACDB1@rac1 /home/oracle$ srvctl stop instance -d racdb -i racdb1 -o immediate
RACDB1@rac1 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application OFFLINE OFFLINE
ora....B2.inst application ONLINE ONLINE rac2
ora....DB1.srv application ONLINE ONLINE rac2
ora.....TAF.cs application ONLINE ONLINE rac2
ora.RACDB.db application ONLINE ONLINE rac2
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
节点2还是可以正常登陆数据库
RACDB2@rac2 /home/oracle$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jul 4 19:39:02 2013
Copyright (c) 1982, 2005, Oracle.All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, Real Application Clusters, OLAP and Data Mining options
SQL>
（2）关闭节点2的RAC实例，当srvctl监测到RAC集群的所有实例都关闭后会自动关闭数据库
RACDB2@rac2 /home/oracle$ srvctl stop instance -d racdb -i racdb2 -o immediate
RACDB2@rac2 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application OFFLINE OFFLINE
ora....B2.inst application OFFLINE OFFLINE
ora....DB1.srv application OFFLINE OFFLINE
ora.....TAF.cs application OFFLINE OFFLINE
ora.RACDB.db application OFFLINE OFFLINE
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
但ASM实例还在启动状态，监听lsnr也在启动状态，application进程也在启动状态
RACDB2@rac2 /home/oracle$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jul 4 19:45:15 2013
Copyright (c) 1982, 2005, Oracle.All rights reserved.
Connected to an idle instance.
SQL>
此时已经不能连接到数据库了
（3）当我们忘了命令语法的时候，直接srvctl就可以查看帮助信息了
RACDB1@rac1 /home/oracle$ srvctl stop asm
PRKO-2001 : Invalid command line syntax
RACDB1@rac1 /home/oracle$ srvctl
Usage: srvctl []
command: enable|disable|start|stop|relocate|status|add|remove|modify|getenv|setenv|unsetenv|config
objects: database|instance|service|nodeapps|asm|listener
For detailed help on each command and object and its options use:
srvctl -h
可以使用-h选项打开帮助信息
RACDB1@rac1 /home/oracle$ srvctl start asm -h
Usage: srvctl start asm -n[-i ] [-o ] [-c| -q]
-n Node name
-i ASM instance name
-o Options to startup command (e.g. open, mount, or nomount)
-c Connect string (default: / as sysdba)
-q Query connect string from standard input
-h Print usage
先关闭节点2的ASM实例
RACDB2@rac2 /home/oracle$ srvctl stop asm -n rac2
RACDB2@rac2 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application OFFLINE OFFLINE
ora....B2.inst application OFFLINE OFFLINE
ora....DB1.srv application OFFLINE OFFLINE
ora.....TAF.cs application OFFLINE OFFLINE
ora.RACDB.db application OFFLINE OFFLINE
ora....SM1.asm application ONLINE ONLINE rac1 节点1的ASM实例还在启动
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application OFFLINE OFFLINE 节点2的ASM实例已经关闭
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
再关闭节点1的ASM实例
RACDB1@rac1 /home/oracle$ srvctl stop asm -n rac1
RACDB1@rac1 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application OFFLINE OFFLINE
ora....B2.inst application OFFLINE OFFLINE
ora....DB1.srv application OFFLINE OFFLINE
ora.....TAF.cs application OFFLINE OFFLINE
ora.RACDB.db application OFFLINE OFFLINE
ora....SM1.asm application OFFLINE OFFLINE
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application OFFLINE OFFLINE
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
我们在把ASM数据库实例启动起来，操作的顺序是相反的
（4）先启动ASM
在节点1和节点2分别启动ASM
RACDB1@rac1 /home/oracle$ srvctl start asm -n rac1
RACDB2@rac2 /home/oracle$ srvctl start asm -n rac2
RACDB2@rac2 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application OFFLINE OFFLINE
ora....B2.inst application OFFLINE OFFLINE
ora....DB1.srv application OFFLINE OFFLINE
ora.....TAF.cs application OFFLINE OFFLINE
ora.RACDB.db application OFFLINE OFFLINE
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
（5）再启动数据库和实例
RACDB1@rac1 /home/oracle$ srvctl start database -d racdb
RACDB1@rac1 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application ONLINE ONLINE rac1
ora....B2.inst application ONLINE ONLINE rac2
ora....DB1.srv application OFFLINE OFFLINE 注意这里service没有启动
ora.....TAF.cs application OFFLINE OFFLINE
ora.RACDB.db application ONLINE ONLINE rac2
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2
（6）再启动服务service
RACDB1@rac1 /home/oracle$ srvctl start service -d racdb
RACDB1@rac1 /home/oracle$ crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora....B1.inst application ONLINE ONLINE rac1
ora....B2.inst application ONLINE ONLINE rac2
ora....DB1.srv application ONLINE ONLINE rac1
ora.....TAF.cs application ONLINE ONLINE rac1
ora.RACDB.db application ONLINE ONLINE rac2
ora....SM1.asm application ONLINE ONLINE rac1
ora....C1.lsnr application ONLINE ONLINE rac1
ora.rac1.gsd application ONLINE ONLINE rac1
ora.rac1.ons application ONLINE ONLINE rac1
ora.rac1.vip application ONLINE ONLINE rac1
ora....SM2.asm application ONLINE ONLINE rac2
ora....C2.lsnr application ONLINE ONLINE rac2
ora.rac2.gsd application ONLINE ONLINE rac2
ora.rac2.ons application ONLINE ONLINE rac2
ora.rac2.vip application ONLINE ONLINE rac2 六分别查看RAC的参数文件，REDO日志，UNDO表空间，TEMP表空间的信息，说明一下在RAC环境下每个实例是否拥有专属自己的上述对象
RAC环境下数据库参数文件的位置
（1）放在各自实例的本地
（2）放在共享存储上，建议使用这种
我们既可以让两个实例使用共享存储上的参数文件
SQL> show parameter spfile;
NAME TYPE VALUE
------------------------------------ ----------- ---------------------------------------------
spfile string +DATA/racdb/spfileracdb.ora共享ASM磁盘上的参数文件
也可以让两个实例使用各自本地的参数文件
$ ll
total 52
-rw-rw---- 1 oracle oinstall1506 Jul8 12:37 ab_+ASM1.dat
-rw-rw---- 1 oracle oinstall1544 Jan12012 hc_+ASM1.dat
-rw-rw---- 1 oracle oinstall1544 Jan12012 hc_RACDB1.dat
lrwxrwxrwx 1 oracle oinstall 41 Jan12012 init+ASM1.ora -> /u01/app/oracle/admin/+ASM/pfile/init.ora
-rw-r----- 1 oracle oinstall 12920 May32001 initdw.ora
-rw-r----- 1 oracle oinstall8385 Sep 111998 init.ora
-rw-r----- 1 oracle oinstall 37 Jan12012 initRACDB1.ora 各自本地的参数文件
如果想使用共享存储上的参数文件，需要在本地参数文件中指定其路径（添加一条spfile重定向），如果不想使用，则无需添加，只在本地参数文件中定义各自实例参数即可。
$ cat initRACDB1.ora
SPFILE='+DATA/RACDB/spfileRACDB.ora'
SQL> select instance_name,host_name,status from gv$instance order by 1;
INSTANCE_NAME HOST_N STATUS
---------------- ------ ----------------------------------
RACDB1 rac1 OPEN
RACDB2 rac2 OPEN
gv$instance：global 动态性能视图，这是在RAC模式下特有的动态性能视图，可以显示所有实例的属性信息。
每个实例都有各自的undo表空间
RAC模式下防止2个实例争用undo回滚段的考虑，每个实例的事务都放在各自的undo表空间上。如果一个实例shutdown，另外的实例可以访问这个实例的undo回滚段。
SQL> select inst_id,name,value from gv$parameter where name='undo_tablespace' order by 1;
INST_ID NAME VALUE
---------- -------------------- ----------------------------------
1 undo_tablespace UNDOTBS1
2 undo_tablespace UNDOTBS2
两个节点的RAC每个节点都有自己的undo表空间
每个实例都有各自的redo日志
RAC模式下每个实例自己管理自己的redo日志，防止争用。如果有一个实例shutdown，另外的实例可以访问这个实例的redo日志用来实例恢复。
SQL> select thread#,group#,sequence#,members,status from v$log;
THREAD# GROUP#SEQUENCE# MEMBERS STATUS
---------- ---------- ---------- ---------- ---------------------------------------------
1 1 8 2 INACTIVE
1 2 9 2 CURRENT
2 3 5 2 INACTIVE
2 4 6 2 CURRENT
Thread#=1 是一个节点的redo日志
Thread#=2 是另一个节点的redo日志
因此每个节点有自己的redo日志
所有实例可以共享TEMP临时表空间
因为temp表空间只是负责排序和hash操作的，不存在空间争用的问题，并且只保存数据中间状态，一旦完成操作可以立即释放资源，因此可以是共享状态。
SQL> select tablespace_name from dba_temp_files;
TABLESPACE_NAME
------------------------------
TEMP
RAC模式下只有一个TEMP表空间 RAC CRS OCR磁盘表决磁盘ASM
Leonarding
2013.07.04
北京&summer
分享技术~成就梦想
Blog：www.leonarding.com
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