DBCA Does Not Display ASM Disk Groups In 11g

Problem - When I launched DBCA as Database home owner e.g. oradb the DBCA gets to the screen to select the disk groups but no Disk Groups are available.    

But when I launch DBCA as Grid infrastructure owner e.g. oragrid the disk groups are available.

Troubleshooting Steps : 

1. Check if your ASM is OK

as Grid Home Owner (e.g. oragrid user ) - The output should be as below 

$ ./crsctl status res -t

…….

ora.asm

ONLINE ONLINE cluster1

ONLINE ONLINE cluster2

{Else srvctl add asm & crsctl start resource ora.asm to start the resource}

2. File permissions in <Grid_home>/bin/oracle executable not set properly.

Solution
As root, change the file permissions of the oracle executable under Grid_Home/bin to 6751:
# cd <Grid_Home>/bin
# chmod 6751 oracle
# ls -l oracle
-rwsr-s--x 1 grid oinstall 173515905 Feb 21 11:06 oracle
This is the setuid bit, and this must be set in order for users, other than "Grid" user to have it work.

3. If the Oracle user is not a part of asmdba group; DBCA will not be able to see the diskgroups, and may not start.

Solution 

In a Job Role Separation  environment (where a separate OS user is used to manage/administer the database and the ASM instances), assign the 'asmdba' role to the db_home owner.

4.The OS environment variable ORA_CRS_HOME is set and set to the wrong Oracle Home. Please avoid setting this environment variable altogether.

Solution

Either unset the ORA_CRS_HOME (recommended) or set this to point to the proper Grid Infrastructure home (GI_home)

Reference : Oracle support note : Oracle support note - ID 1177483.1