oracle版本为11.2.0.3，系统版本为Centos Linux 6.6 X86_64,安装完成grid软件后，一切正常，没有报错，但是使用sqlplus / as sysasm后提示连接到空闲进程

[grid@oracle dbs]$ sqlplus / as sysasm;SQL*Plus: Release 11.2.0.3.0 Production on Mon Apr 25 15:08:06 2016Copyright (c) 1982, 2011, Oracle.  All rights reserved.Connected to an idle instance.SQL> startup mount;
ORA-15149: another ASM instance found running on the host

检查css状态

[grid@oracle ~]$ crs_stat -t
Name           Type           Target    State     Host
------------------------------------------------------------
ora.DATA.dg    ora....up.type ONLINE    ONLINE    oracle
ora....ER.lsnr ora....er.type ONLINE    ONLINE    oracle
ora.asm        ora.asm.type   ONLINE    ONLINE    oracle
ora.cssd       ora.cssd.type  ONLINE    ONLINE    oracle
ora.diskmon    ora....on.type OFFLINE   OFFLINE
ora.evmd       ora.evm.type   ONLINE    ONLINE    oracle
ora.ons        ora.ons.type   OFFLINE   OFFLINE
ora.orcl.db    ora....se.type ONLINE    ONLINE    oracle

发现ora.diskmon为offline状态，查阅资料后发现从11.2.0.3版本开始默认diskmon在非exadata上是禁用状态

11.2.0.3 Grid Infrastructure diskmon Will be Offline by Default in Non-Exadata Environment [ID 1346881.1]

百般折腾看是否有办法启用ora.diskmon,设置auto_start为1也没有效果，检查asm进程

[grid@oracle grid]$ ps -ef|grep asm_
grid      25991      1  0 14:56 ?        00:00:00 asm_pmon_+ASM
grid      25993      1  0 14:56 ?        00:00:00 asm_psp0_+ASM
grid      26019      1  2 14:56 ?        00:00:18 asm_vktm_+ASM
grid      26023      1  0 14:56 ?        00:00:00 asm_gen0_+ASM
grid      26025      1  0 14:56 ?        00:00:00 asm_diag_+ASM
grid      26027      1  0 14:56 ?        00:00:00 asm_dia0_+ASM
grid      26029      1  0 14:56 ?        00:00:00 asm_mman_+ASM
grid      26031      1  0 14:56 ?        00:00:00 asm_dbw0_+ASM
grid      26033      1  0 14:56 ?        00:00:00 asm_lgwr_+ASM
grid      26035      1  0 14:56 ?        00:00:00 asm_ckpt_+ASM
grid      26037      1  0 14:56 ?        00:00:00 asm_smon_+ASM
grid      26039      1  0 14:56 ?        00:00:00 asm_rbal_+ASM
grid      26041      1  0 14:56 ?        00:00:00 asm_gmon_+ASM
grid      26043      1  0 14:56 ?        00:00:00 asm_mmon_+ASM
grid      26045      1  0 14:56 ?        00:00:00 asm_mmnl_+ASM
grid      29065  25763  0 15:10 pts/4    00:00:00 grep asm_

检查监听状态

[grid@oracle ~]$ lsnrctl statusLSNRCTL for Linux: Version 11.2.0.3.0 - Production on 25-APR-2016 14:56:58Copyright (c) 1991, 2011, Oracle.  All rights reserved.Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date                25-APR-2016 14:55:38
Uptime                    0 days 0 hr. 1 min. 20 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/grid/network/admin/listener.ora
Listener Log File         /u01/app/diag/tnslsnr/oracle/listener/alert/log.xml
Listening Endpoints Summary...(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle.study)(PORT=1521)))
Services Summary...
Service "+ASM" has 1 instance(s).Instance "+ASM", status READY, has 1 handler(s) for this service...
Service "orcl" has 1 instance(s).Instance "orcl", status READY, has 1 handler(s) for this service...
Service "orclXDB" has 1 instance(s).Instance "orcl", status READY, has 1 handler(s) for this service...
The command completed successfully

监听状态正常

检查参数文件init+asm.ora也没发现问题

[grid@oracle dbs]$ cat init+asm.ora
*.asm_power_limit=1
*.instance_type='asm'
*.large_pool_size=12M
*.remote_login_passwordfile='EXCLUSIVE'
*.asm_diskstring='/dev/asm-disk*'

最后检查.bash_profile文件配置

[grid@oracle dbs]$ cat ~/.bash_profile
# .bash_profile# Get the aliases and functions
if [ -f ~/.bashrc ]; then. ~/.bashrc
fi# User specific environment and startup programsORACLE_BASE=/u01/app; export ORACLE_BASE
ORACLE_HOME=/u01/app/grid; export ORACLE_HOME
ORACLE_SID=+asm; export ORACLE_SID
export LD_LIBRARY_PATH=$ORACLE_HOME/lib
PATH=$PATH:$HOME/bin:$ORACLE_HOME/binexport PATH

ORACLE_SID为小写的+asm,而实际进程中的为大写+ASM，oracle区分大小写，改为大写后再连接后就正常了

[grid@oracle grid]$ export ORACLE_SID=+ASM
[grid@oracle grid]$ sqlplus / as sysasm;SQL*Plus: Release 11.2.0.3.0 Production on Mon Apr 25 15:11:28 2016Copyright (c) 1982, 2011, Oracle.  All rights reserved.Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Automatic Storage Management optionSQL> show parameter diskgroupNAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
asm_diskgroups                       string

连接后OK