Unable to view/list diskgroups in asm command prompt

 
ASM Disk Group issue:
 
Issue : Unable to view/list diskgroups in asm command prompt
 
Cause: asm_diskstring is set as "/dev/sd*" in asm pfile
Identified the labelled disks from the below queries
#>  oracleasm querydisk /dev/sdb1
Device "/dev/sdb1" is marked an ASM disk with the label "DATA"
[root@app1:/dev]
#>  oracleasm querydisk /dev/sdb2
Device "/dev/sdb2" is marked an ASM disk with the label "FRA"
 
Resolution: Modified the pfile with labelled disks as below and brought up the asm services
asm_diskstring           = "/dev/sdb*"                                          
 
Now, able to view/list the asm disks