ASMLib: oracleasm createdisk command fails: Device '/dev/emcpowera1 is not a partition

    悲催的一天，在redhat linux 5.4上搭建oracle10g rac，多路径软件为EMC PowerPath5.3在安装搞asm的时候连续遇到问题，先是在运行/etc/init.d/oracleasm configure的时候报错，传说出现这个问题是因为selinux 是非disable的活着asm包安装有问题，瞪大眼睛检查了又检查竟然没发现要装的是结果还是因为asm包装的有问题。最后在创建asmdisk的时候又遭遇BUG:6605620

In this Document
  Symptoms
  Changes
  Cause
  Solution
  References

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Applies to:

Linux OS - Version: 2.0.3-1 and later   [Release: OEL4 and later ]
Linux x86
Linux x86-64
Linux Kernel - Version: 2.0.3-1

Symptoms

The "oracleasm createdisk" command fails with the following error despite the device having been correctly partitioned:

Marking disk "/dev/emcpowera1" as an ASM disk: asmtool: Device "/dev/emcpowera1" is not a
partition         [FAILED]

 

Changes

You are using EMC PowerPath version <= 5.3.0

Cause

EMC PowerPath versions <= 5.3.0 do not properly support the I/O calls performed by oracleasm.

Solution

The issue is resolved with EMC PowerPath version 5.3 SP1 (5.3.1) - refer:

• EMC� PowerPath Family for Linux Version 5.3 Release Notes - January 25, 2010 (Fixed Problems)
• EMC Knowledgebase Solution emc203137

EMC PowerPath 5.3.1 is readily available from EMC's Powerlink website (login required) i.e.:

http://powerlink.emc.com > Support > Software Downloads & Licensing > Downloads P-R > Powerpath for Linux

If it is not currently possible to upgrade to the latest version of PowerPath containing the fix, the following workaround is possible:

1. Perform the "oracleasm createdisk" operation using the "asmtool" command directly e.g.:

# /usr/sbin/asmtool -C -l /dev/oracleasm -n VOL1 -s /dev/emcpowera1 -a force=yes

The asmtool will (expectedly) report the following:

asmtool: Device "/dev/emcpowera1" is not a partition
asmtool: Continuing anyway
...

2. The user/group ownership of the resultant devices under directory /dev/oracleasm/disks/ will be "root:root" therefore may not be immediately accessible to other user processes.

However, ownership can be manually modified using the chown(1) command. Specify the user:group as defined in oracleasm configuration file /etc/sysconfig/oracleasm (ORACLEASM_UID, ORACLEASM_GID) or by restarting  the oracleasm service e.g.:

# /sbin/service oracleasm restart

If restarting the oracleasm service is not effective, system reboot is required.

3. Once the asmdisk has been successfully created, further use of the device can now be performed normally using the "/etc/init.d/oracleasm" command against the PowerPath pseudo device e.g. /dev/emcpowera1.

References

BUG:6605620 - ORACLEASM CREATEDISK FAILS: DEVICE "/DEV/EMCPOWERB2" IS NOT A PARTITION [FAILED]