Creating ASM diskgroup

Rac1:

SQL> select name from v$asm_diskgroup;

NAME
------------------------------
CRSDG

SQL> select path from v$asm_disk;

PATH
--------------------------------------------------------------------------------
/dev/oracleasm/disks/FRAVOL
/dev/oracleasm/disks/DATAVOL
/dev/oracleasm/disks/CRSVOL

SQL> conn /as sysasm
Connected.
SQL> create diskgroup DATADG external REDUNDANCY disk '/dev/oracleasm/disks/DATAVOL';

Diskgroup created.

SQL> create diskgroup FRADG external REDUNDANCY disk '/dev/oracleasm/disks/FRAVOL';

Diskgroup created.

SQL>



Rac2:

SQL> select group_number,name,state,total_mb from v$asm_diskgroup;

GROUP_NUMBER NAME STATE TOTAL_MB
------------ ------------------------------ ----------- ----------
1 CRSDG MOUNTED 2205
0 FRADG DISMOUNTED 0
0 DATADG DISMOUNTED 0

SQL> alter diskgroup DATADG mount;

Diskgroup altered.

SQL> alter diskgroup FRADG mount;

Diskgroup altered.

SQL> select group_number,name,state,total_mb from v$asm_diskgroup;

GROUP_NUMBER NAME STATE TOTAL_MB
------------ ------------------------------ ----------- ----------
1 CRSDG MOUNTED 2205
3 FRADG MOUNTED 39839
2 DATADG MOUNTED 39839

SQL>



**Additionally

On one occasion, I notice the diskgroup was not available during database creation.
I checked the resources. FRADG was OFFLINE on rac2, even though I just created and mounted it.

NAME=ora.FRADG.dg
TYPE=ora.diskgroup.type
TARGET=ONLINE , OFFLINE
STATE=ONLINE on rac1, OFFLINE

Go back and remount it:

SQL> alter diskgroup FRADG dismount;

Diskgroup altered.

SQL> alter diskgroup FRADG mount;

Diskgroup altered.

And now, the resource shows ONLINE on rac2:

NAME=ora.FRADG.dg
TYPE=ora.diskgroup.type
TARGET=ONLINE , ONLINE
STATE=ONLINE on rac1, ONLINE on rac2