ORACLE RAC删除RAC节点删除RAC节点有分为2种情况，一种是2台RAC节点都完好，但是要删除其中一个节点，另外一种情况是，某个RAC节点由于硬件问题或者软件问题出现问题导致机器已经关闭。
2种情况的删除其实都可以使用后一种方法来做，即直接通过操作来清除OCR和voting disk的RAC节点信息。
但是当你一个完好的RAC我们还是使用正规的删除方法。
先介绍一个完好无损的RAC删除节点的方法：[root@rac1 ~]# /u01/app/crs/bin/crs_stat -tName Type Target State Host------------------------------------------------------------ora.orcl.db application ONLINE ONLINE rac1ora....l1.inst application ONLINE ONLINE rac1ora....l2.inst application ONLINE ONLINE rac2ora....SM1.asm application ONLINE ONLINE rac1ora....C1.lsnr application ONLINE ONLINE rac1ora.rac1.gsd application ONLINE ONLINE rac1ora.rac1.ons application ONLINE ONLINE rac1ora.rac1.vip application ONLINE ONLINE rac1ora....SM2.asm application ONLINE ONLINE rac2ora....C2.lsnr application ONLINE ONLINE rac2ora.rac2.gsd application ONLINE ONLINE rac2ora.rac2.ons application ONLINE ONLINE rac2ora.rac2.vip application ONLINE ONLINE rac2以上是一个非常正常的RAC。
下面来删除节点RAC2.在删除之前简单介绍一下RAC结构的构成，在RAC当中，每个服务诸如database,listener,ons,gsd等都是一个service注册在OCR当中以及节点信息存储在voting disk。
所以在删除时也同样是以删除注册信息的方式来达到目的。
一般的删除步骤为：删除database--->删除ORACLE_HOME信息—>删除CRS_HOME信息综合上面，其实就是先清除ORACLE本身服务信息,然后再清除CRS服务信息.下面开始删除动作：1)启动dbca（在保留节点启动），删除instance.检查CRS状态：[root@rac2 ~]# /u01/app/crs/bin/crs_stat -tName Type Target State Host------------------------------------------------------------ora.orcl.db application ONLINE ONLINE rac1ora....l1.inst application ONLINE ONLINE rac1ora....SM1.asm application ONLINE ONLINE rac1ora....C1.lsnr application ONLINE ONLINE rac1ora.rac1.gsd application ONLINE ONLINE rac1ora.rac1.ons application ONLINE ONLINE rac1ora.rac1.vip application ONLINE ONLINE rac1ora....SM2.asm application ONLINE ONLINE rac2ora....C2.lsnr application ONLINE ONLINE rac2ora.rac2.gsd application ONLINE ONLINE rac2ora.rac2.ons application ONLINE ONLINE rac2ora.rac2.vip application ONLINE ONLINE rac2可以看到rac2的instance信息已经消失了。
表示删除instance完毕。
2）删除RAC2的ASM先停止RAC2的ASM instance: srvctl stop asm -n rac2删除ASM home目录：[oracle@rac2 admin]$ pwd/u01/app/oracle/admin , rm -rf +ASM3)删除rac2 listener,启动netca（在删除节点运行）检查CRS服务：[oracle@rac1 ~]$ /u01/app/crs/bin/crs_stat -tName Type Target State Host------------------------------------------------------------ora.orcl.db application ONLINE ONLINE rac1ora....l1.inst application ONLINE ONLINE rac1ora....SM1.asm application ONLINE ONLINE rac1ora....C1.lsnr application ONLINE ONLINE rac1ora.rac1.gsd application ONLINE ONLINE rac1ora.rac1.ons application ONLINE ONLINE rac1ora.rac1.vip application ONLINE ONLINE rac1ora....SM2.asm application OFFLINE OFFLINEora....C2.lsnr application OFFLINE OFFLINEora.rac2.gsd application ONLINE ONLINE rac2ora.rac2.ons application ONLINE ONLINE rac2ora.rac2.vip application ONLINE ONLINE rac2可以看到ASM和listener_rac2已经OFFline但是此时listener只是offline，并没有从OCR移除，通过下面方法来移除：/u01/app/crs/bin/crs_unregister ora.rac2.LISTENER_RAC2.lsnr（ORACLE RAC修改listener只有通过NETCA才可以做到，所以也可以通过进入cluster instance去删除listener，然后在保留节点新建listener方法，这样就可以直接移除OCR信息，而不需要通过/u01/app/crs/bin/crs_unregister ）srvctl remove asm -n rac2 移除ASM实例Name Type Target State Host------------------------------------------------------------ora.orcl.db application ONLINE ONLINE rac1ora....l1.inst application ONLINE ONLINE rac1ora....SM1.asm application ONLINE ONLINE rac1ora....C1.lsnr application ONLINE ONLINE rac1ora.rac1.gsd application ONLINE ONLINE rac1ora.rac1.ons application ONLINE ONLINE rac1ora.rac1.vip application ONLINE ONLINE rac1ora.rac2.vip application OFFLINE OFFLINE4）更新ORACLE_HOME信息(保留节点运行)[oracle@rac1 bin]$ ./runInstaller -updateNodeListORACLE_HOME=/u01/app/oracle/product/10.2.0/db_1 "CLUSTER_NODES=rac1"Starting Oracle Universal Installer...No pre-requisite checks found in oraparam.ini, no system pre-requisite checks will beexecuted.'UpdateNodeList' was successful.5）移除VIP信息和ONS服务racgons remove_config rac2:6200 （保留节点运行）oifcfg delif -node rac2 (保留节点运行)6) 删除RAC2节点CRS服务，进入/u01/app/crs/install目录，执行rootdelete.sh [root@rac2 install]# ./rootdelete.sh （在删除节点运行）CRS-0210: Could not find resource 'ora.rac2.LISTENER_RAC2.lsnr'.Shutting down Oracle Cluster Ready Services (CRS):Stopping resources.Successfully stopped CRS resourcesStopping CSSD.Shutting down CSS daemon.Shutdown request successfully issued.Shutdown has begun. The daemons should exit soon. Checking to see if Oracle CRS stack is down...Oracle CRS stack is not running.Oracle CRS stack is down now.Removing script for Oracle Cluster Ready servicesUpdating ocr file for downgradeCleaning up SCR settings in '/etc/oracle/scls_scr'[oracle@rac1 bin]$ /u01/app/crs/bin/crs_stat -tName Type Target State Host------------------------------------------------------------ora.orcl.db application ONLINE ONLINE rac1 ora....l1.inst application ONLINE ONLINE rac1 ora....SM1.asm application ONLINE ONLINE rac1 ora....C1.lsnr application ONLINE ONLINE rac1ora.rac1.gsd application ONLINE ONLINE rac1ora.rac1.ons application ONLINE ONLINE rac1ora.rac1.vip application ONLINE ONLINE rac1 ora....SM2.asm application OFFLINE OFFLINEora.rac2.vip application OFFLINE OFFLINE可以看到nodeapps服务全部已经从OCR删除了。