操作前建议检查相关信息，如集群状态、数据库运行情况等，最好最一个备份。
########移除数据库########
--通过DBCA方式删除节点（此处举例rac03），请在rac01/02运行，如不说明，默认情况下rac03运行
--查看数据库运行情况
set lines 150
col instance for a30
select t.inst_id,t.thread#,t.status,t.instance from gv$thread t;
ALTER DATABASE DISABLE THREAD 3
---停止监听
srvctl disable listener -l listener -n rac03
srvctl stop listener -l listener -n rac03
--更新查看列表
[oracle@rac03 ~]$ cd $ORACLE_HOME/oui/bin
[oracle@rac03 bin]$ ./runInstaller -updateNodeList ORACLE_HOME=/u02/app/oracle/product/11.2.0/db_home "CLUSTER_NODES={rac03}" -local
Starting Oracle Universal Installer...
Checking swap space: must be greater than 500 MB. Actual 4769 MB Passed
The inventory pointer is located at /etc/oraInst.loc
The inventory is located at /u01/app/oraInventory
'UpdateNodeList' was successful.
[oracle@rac03 bin]$
--移除数据库实例节点
./deinstall -local
…………………………
Cleaning the config for CCR
As CCR is not configured, so skipping the cleaning of CCR configuration
CCR clean is finished
Successfully detached Oracle home '/u02/app/oracle/product/11.2.0/db_home' from the central inventory on the local node.
Successfully deleted directory '/u02/app/oracle/product/11.2.0/db_home' on the local node.
Oracle Universal Installer cleanup was successful.
Oracle deinstall tool successfully cleaned up temporary directories.
#######################################################################
############# ORACLE DEINSTALL & DECONFIG TOOL END #############
--更新其他的节点的inventory RAC01/02执行
./runInstaller -updateNodeList ORACLE_HOME=/u02/app/oracle/product/11.2.0/db_home "CLUSTER_NODES={rac1,rac2}"
###########移除 grid#################
--查看状态 olsnodes -s -t
--移除节点grid资源配置 root用户
/u01/app/11.2.0/grid/crs/install/rootcrs.pl -deconfig -force
………………
CRS-2673: Attempting to stop 'ora.cssd' on 'rac03'
CRS-2677: Stop of 'ora.cssd' on 'rac03' succeeded
CRS-2673: Attempting to stop 'ora.gipcd' on 'rac03'
CRS-2677: Stop of 'ora.gipcd' on 'rac03' succeeded
CRS-2673: Attempting to stop 'ora.gpnpd' on 'rac03'
CRS-2677: Stop of 'ora.gpnpd' on 'rac03' succeeded
CRS-2793: Shutdown of Oracle High Availability Services-managed resources on 'rac03' has completed
CRS-4133: Oracle High Availability Services has been stopped.
Successfully deconfigured Oracle clusterware stack on this node
--删除grid节点 RAC01/02执行 root用户
/u01/app/11.2.0/grid/bin/crsctl delete node -n rac03
--更新删除节点目录信息
/u01/app/11.2.0/grid/oui/bin/runInstaller -updateNodeList ORACLE_HOME=/u01/app/11.2.0/grid "CLUSTER_NODES={rac03}" CRS=TRUE -local
--卸载集群
/u01/app/11.2.0/grid/deinstall/deinstall –local
-更新inventory RAC01/02执行
/u01/app/11.2.0/grid/oui/bin/runInstaller -updateNodeList ORACLE_HOME=/u01/app/11.2.0/grid "CLUSTER_NODES={rac01,rac02}" CRS=TRUE
--验证节点是否删除成功 RAC01/02执行
[grid@rac02 ~]$ cluvfy stage -post nodedel -n rac03 -verbose
Performing post-checks for node removal
Checking CRS integrity...
Clusterware version consistency passed
The Oracle Clusterware is healthy on node "rac02"
The Oracle Clusterware is healthy on node "rac01"
CRS integrity check passed
Result:
Node removal check passed
Post-check for node removal was successful.