Oracle 11g RAC 创建实例DBCA无法发现ASM Diskgroup

Oracle 11g RAC 创建实例DBCA无法发现ASM Diskgroup2010-10-16 23:10:11
分类：Linux
安装Oracle 11gR2 RAC 的时候执行创建实例，DBCA老是找不到之前通过asmca 工具创建好的ASM DiskGroup。

查了METALINK：
ASM is Unable to Detect ASMLIB Disks/Devices. [ID 457369.1]
修改时间 03-DEC-2009 类型 HOWTO 状态 PUBLISHED
In this Document
Goal
Solution
Applies to:
Oracle Server - Enterprise Edition - Version: 10.2.0.1 to 11.1.0.6
Linux x86
Linux x86-64
Goal
This documented can be used to detect ASMLIB devices/disks thru the ASM instance. Solution
1) First of all, please scan the disks (on all the nodes if RAC):
:+ASM:oracle:11g>/etc/init.d/oracleasm scandisks
Scanning system for ASM disks: OK ]
2) Second, make sure the disks can be listed :
:+ASM:oracle:11g>/etc/init.d/oracleasm listdisks
VOL1_10G
VOL2_10G
3) Query each disks:
:+ASM:oracle:11g>/etc/init.d/oracleasm querydisk VOL1_10G
Disk "VOL1_10G" is a valid ASM disk on device [3, 18]
:+ASM:oracle:11g>/etc/init.d/oracleasm querydisk VOL2_10G
Disk "VOL2_10G" is a valid ASM disk on device [3, 22]
4) Check if they exist at OS level:
:+ASM:oracle:11g>ls -l /dev/oracleasm/disks/VOL1_10G
brw-rw---- 1 oracle dba 3, 18 Aug 13 09:54 /dev/oracleasm/disks/VOL1_10G
:+ASM:oracle:11g>ls -l /dev/oracleasm/disks/VOL2_10G
brw-rw---- 1 oracle dba 3, 22 Aug 13 09:55 /dev/oracleasm/disks/VOL2_10G
5) Then, in the initialization parameter file set the discovery disks string parameter as follow:
asm_diskstring =ORCL:*
Note: Also, you can set it thru the DBCA (during the diskgroup(s) creation) by pressing the [Change Disk Discovery Path] button.
6) If the problem persists then you can set the discovery disks string as follow:
asm_diskstring = /dev/oracleasm/disks/*
7) As workaround you can setasm_diskstring = /dev/oracleasm/disks/*, this is possible for Oracle 10g Release 2 and onwards since it can access block devices. Oracle uses O_DIRECT flag, which can be used for opening block devices to bypass the OS cache.
8) If the problem persists, please open a new service request with Oracle support and then please provide us the next information (from all the nodes if RAC) :
Upload the next files:
=======================================
=)> /var/log/messages
=)> New /etc/sysconfig/oracleasm
=)> alert+ASM#.log for each instance.
================================
And the output of the next commands
================================
$> cat /etc/*release
$> uname -a
$> rpm -qa |grep oracleasm
$> df -ha
$> ls -l /dev/oracleasm/disks
$> powermt display dev=emcpower# (On all the partitions if using PowerPath from EMC)
================================
$> /etc/init.d/oracleasm status
$> usr/sbin/oracleasm-discover
$> /usr/sbin/oracleasm-discover 'ORCL:*'
================================
SQL> show parameter asm
=======================================。