OUI not able to find the ASM disks .. why?

There might be a chance that the following scenario can occur at any time.

Verify all the asm related rpms installed.

The main rpm "oracleasmlib*.rpm" is installed . 

The main executable required for the oracle asm discovery is : oracleasm-discover.



oracleasm can identify the disks after creating them using

oracleasm createdisk OCR /dev/sdb1
oracleasm createdisk VOTING /dev/sdb2
oracleasm createdisk ASMDISK1 /dev/sdb3

once the creation is done

oracleasm listdisks

OCR
VOTING
ASMDISK1

but when you try installing 11g grid infrastructure OUI might not know these disks.

Please check the permissions of the user you are using to create/install grid infrastructure.

Make sure you have " asmdba " added to the user.

Make sure the devices are mapped in /etc/sysconfig/rawdevices file

make sure the raw disks that you have "oracle/grid: dba/asmdba" privileges to them

and make sure the disks should have 660 permissions and then map the Change Discovery Path in OUI to point to the rawdevices location and see.


ex: if the grid infrasture is going to be installed with 'oracle' user.

chown oracle:dba /dev/raw/raw*
chmod 660 /dev/raw/raw*

or

chown oracle:dba /dev/oracleasm/disks/*
chmod 660 /dev/oracleasm/disks/*


Reference:-  http://cheatsheet4oracledba.blogspot.com/2012/08/oui-not-able-to-find-asm-disks-why.html