Oracle ASM Disk - Mount Status IGNORED With Group Number 0

Symptoms:

1. select * from gv$asm_disk
Shows records with GROUP_NUMBER = 0, HEADER_STATUS = MEMBER, MOUNT_STATUS = IGNORED

2. check if both rac instances has access to specified disk

- Devices ids in /dev/oracleasm/disks/*

- Devices list according to ids /dev/*

3. If everything is ok remount with force option:

ALTER DISKGROUP DATA ADD FAILGROUP FG_NAME DISK '/dev/oracleasm/disks/DISK' NAME DISKNAME force;

Main Resource : V$ASM_DISK View Shows Some Disk Header Status as IGNORED and Group Number as "0". (Doc ID 1299866.1)