1. 查看crs状态
$ crs_stat -t
Name Type Target State Host   
------------------------------------------------------------
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....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   
ora.racdb.db application ONLINE ONLINE rac2   
ora....acdb.cs application ONLINE ONLINE rac1   
ora....db1.srv application ONLINE ONLINE rac1   
ora....db2.srv application ONLINE OFFLINE   
ora....b1.inst application ONLINE ONLINE rac1   
ora....b2.inst application ONLINE OFFLINE  

2。查看数据库状态
$ srvctl status database -d racdb
Instance racdb1 is running on node rac1
Instance racdb2 is not running on node rac2 --rac2节点没有运行实例

3。启动实例
$ srvctl start instance -d racdb -i racdb2
PRKP-1001 : Error starting instance racdb2 on node rac2
CRS-0215: Could not start resource 'ora.racdb.racdb2.inst'.

发日志，- - 不然怎么知道啥问题啊

将日志贴出来，或者发到我的邮箱里面。
日志可以是alert日志即可。