rac第二个节点重启后无法启动实例：磁盘组dismount问题 实验案例： 实验环境：centos 6.4、oracle 11.2.0.1 现象重演： 1. 重启第二节点服务器 2. 手工启动第二节点实例，报错 [root@node2 ~]# su - oracle[oracle@node2 ~]$ sqlplus /as sysdbasql*plus: re
rac第二个节点重启后无法启动实例：磁盘组dismount问题
实验案例：
实验环境：centos 6.4、oracle 11.2.0.1
现象重演：
1. 重启第二节点服务器
2. 手工启动第二节点实例，报错
[root@node2 ~]# su - oracle[oracle@node2 ~]$ sqlplus '/as sysdba'sql*plus: release 11.2.0.1.0 production on sun nov 23 15:11:04 2014copyright (c) 1982, 2009, oracle. all rights reserved.connected to an idle instance.
启动数据库报错如下：
sql> startupora-01078: failure in processing system parametersora-01565: error in identifying file '+dg1/xcky/spfilexcky.ora'ora-17503: ksfdopn:2 failed to open file +dg1/xcky/spfilexcky.oraora-15056: additional error messageora-17503: ksfdopn:dgopenfile05 failed to open file +dg1/xcky/spfilexcky.oraora-17503: ksfdopn:2 failed to open file +dg1/xcky/spfilexcky.oraora-15001: diskgroup dg1 does not exist or is not mountedora-06512: at line 4
根据上面的错误，锁定到ora-15001错误，这是代表有磁盘组没有mount，于是按照这个思路进行查看。
3. grid用户下，查看磁盘组状态
[root@node2 ~]# su - grid[grid@node2 ~]$ sqlplus '/as sysdba'sql*plus: release 11.2.0.1.0 production on sun nov 23 15:27:04 2014copyright (c) 1982, 2009, oracle. all rights reserved.connected to:oracle database 11g enterprise edition release 11.2.0.1.0 - 64bit productionwith the real application clusters and automatic storage management optionssql> select name,state from v$asm_diskgroup;name state------------------------------ -----------crs mounteddg1 dismountedrcy1 dismounted
可以发现，dg1、rcy1磁盘组处于dismounted状态，于是手工启动到mount状态，如下操作：
4. 启动磁盘组到mount状态
需要注意，对磁盘组操作时，需要使用sysasm用户，该用户有对磁盘组操作的权限，如下：
sql> conn /as sysasmconnected.sql> select name,state from v$asm_diskgroup;name state------------------------------ -----------crs mounteddg1 dismountedrcy1 dismountedsql> alter diskgroup dg1 mount;diskgroup altered.sql> alter diskgroup rcy1 mount;diskgroup altered.sql> select name,state from v$asm_diskgroup;name state------------------------------ -----------crs mounteddg1 mountedrcy1 mounted至此，完成了将全部磁盘组启动到mount状态。5. 再次启动节点2的实例[root@node2 ~]# su - oracle[oracle@node2 ~]$ sqlplus '/as sysdba'sql*plus: release 11.2.0.1.0 production on sun nov 23 15:31:11 2014copyright (c) 1982, 2009, oracle. all rights reserved.connected to an idle instance.sql> startuporacle instance started.total system global area 730714112 bytesfixed size 2216944 bytesvariable size 557845520 bytesdatabase buffers 167772160 bytesredo buffers 2879488 bytesdatabase mounted.database opened.sql> select status,instance_name from gv$instance;--查询整个集群环境，可以看到两个节点都已经启动了status instance_name------------ ----------------open xcky2open xcky1
至此，由于磁盘组处于dismount状态引起的单节点实例无法启动问题，解决。