系统环境：
操作系统：RedHat EL5
Cluster： Oracle 11gR2 Grid
Oracle： Oracle 11gR2
RAC环境中，其中一个节点crsd进程启动失败：
[grid@wyb666 ~]$ crsctl check crs
CRS-4638: Oracle High Availability Services is online
CRS-4535: Cannot communicate with Cluster Ready Services
CRS-4529: Cluster Synchronization Services is online
CRS-4533: Event Manager is online
1、查看日志
[root@wyb666 ~]# cd /u01/11.2.0/grid/log
[root@wyb666 log]# ls
crs diag wyb666
[root@wyb666 log]# cd wyb666/
[root@wyb666 wyb666]# ls
admin alertwyb666.log crsd ctssd evmd gnsd mdnsd racg
agent client cssd diskmon gipcd gpnpd ohasd srvm
[root@wyb666 wyb666]# cd crsd
[root@wyb666 crsd]# ls
crsd.log crsdOUT.log crsd.trc
[root@wyb666 crsd]# tail crsd.log
2015-06-08 11:41:28.430: [ OCRASM][3046103824]proprasmcl: asmhandle is NULL
2015-06-08 11:41:28.430: [ OCRRAW][3046103824]proprinit: Could not open raw device
2015-06-08 11:41:28.430: [ OCRASM][3046103824]proprasmcl: asmhandle is NULL
2015-06-08 11:41:28.430: [ OCRAPI][3046103824]a_init:16!: Backend init unsuccessful : [26]
2015-06-08 11:41:28.430: [ CRSOCR][3046103824] OCR context init failure. Error: PROC-26: Error while accessing the physical storage ASM error [SLOS: cat=7, opn=kgfoAl06, dep=15077, loc=kgfokge
ORA-15077: could not locate ASM instance serving a required diskgroup
] [7]
2015-06-08 11:41:28.430: [ CRSD][3046103824][PANIC] CRSD exiting: Could not init OCR, code: 26
2015-06-08 11:41:28.430: [ CRSD][3046103824] Done.
从以上可以看出：在crs service启动时，无法访问OCR磁盘，访问ASM DISKGROUP 失败！
2、查看ASM磁盘组信息
[root@wyb666 crsd]# service oracleasm listdisks
ASM_DATA1
ASM_DATA2
ASM_RCY1
ASM_RCY2
OCR_VOTE1
OCR_VOTE2
OCR_VOTE3
[root@wyb666 crsd]# ls -l /dev/oracleasm/disks
total 0
brw-rw---- 1 grid asmadmin 8, 21 Jun 8 09:23 ASM_DATA1
brw-rw---- 1 grid asmadmin 8, 22 Jun 8 09:23 ASM_DATA2
brw-rw---- 1 grid asmadmin 8, 23 Jun 8 09:23 ASM_RCY1
brw-rw---- 1 grid asmadmin 8, 24 Jun 8 09:23 ASM_RCY2
brw-rw---- 1 grid asmadmin 8, 17 Jun 8 11:53 OCR_VOTE1
brw-rw---- 1 grid asmadmin 8, 18 Jun 8 11:53 OCR_VOTE2
brw-rw---- 1 grid asmadmin 8, 19 Jun 8 11:53 OCR_VOTE3
解决方法：
重新启动CRS服务，然后再手工启动ASM Instance：
启动ASM Instance
[root@wyb666 crsd]# su - grid
[grid@wyb666 ~]$ sqlplus '/as sysasm'
SQL*Plus: Release 11.2.0.1.0 Production on Mon Jun 8 11:59:26 2015
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
SQL> conn /as sysasm
Connected to an idle instance.
SQL> startup
ASM instance started
Total System Global Area 284565504 bytes
Fixed Size 1336036 bytes
Variable Size 258063644 bytes
ASM Cache 25165824 bytes
ASM diskgroups mounted
ASM diskgroups volume enabled
SQL> select name,state from v$asm_diskgroup;
NAME STATE
------------------------------ -----------
DATA MOUNTED
DG1 MOUNTED
RCY1 MOUNTED
启动成功：
[root@wyb666 ~]# crsctl check crs
CRS-4638: Oracle High Availability Services is online
CRS-4537: Cluster Ready Services is online
CRS-4529: Cluster Synchronization Services is online
CRS-4533: Event Manager is online
