Oracle 11g RAC 建立例項DBCA無法發現ASM Diskgroup

In this Document
  Goal
  Solution

Applies to:

Goal

Solution

1) First of all, please scan the disks (on all the nodes if RAC):

dbaasm.us.oracle.com:+ASM:oracle:11g>/etc/init.d/oracleasm scandisks 
Scanning system for ASM disks: OK ] 

2) Second, make sure the disks can be listed :

dbaasm.us.oracle.com:+ASM:oracle:11g>/etc/init.d/oracleasm listdisks 
VOL1_10G 
VOL2_10G 

3) Query each disks: 

dbaasm.us.oracle.com:+ASM:oracle:11g>/etc/init.d/oracleasm querydisk VOL1_10G 
Disk "VOL1_10G" is a valid ASM disk on device [3, 18] 
dbaasm.us.oracle.com:+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: 

dbaasm.us.oracle.com:+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 
dbaasm.us.oracle.com:+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:

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=)> /var/log/messages

=)> New /etc/sysconfig/oracleasm 

=)> alert+ASM#.log for each instance. 
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And the output of the next commands

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$> 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)

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$> /etc/init.d/oracleasm status 
$> usr/sbin/oracleasm-discover 
$> /usr/sbin/oracleasm-discover 'ORCL:*' 

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SQL> show parameter asm 
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