ASM Disk Creation Fails with EMC PowerPath

Creating an ASM disk with oracleasm createdisk fails with

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

even though multipathing is setup correctly.

According to metalink note 469163.1 ASMLib: oracleasm createdisk command fails: Device '/dev/emcpowera1 is not a partition this is due to the PowerPath version is less than 5.3.0.

In spite this error ASM disks could be created using asmtool by specifying the force option.

# /usr/sbin/asmtool -C -l /dev/oracleasm -n DATA01 -s /dev/emcpowera1 -a force=yes

Once created the disk will be visible through listdisks command and running a scandisks on other nodes in the cluster will make it discoverable on these nodes as well.

Another related metalink note is 566676.1 How To Determinate If An EMCPOWER Partition Is Valid For ASMLIB? which list a different cause for the problem but error message shown is same as above.