Post date: 22-May-2009 08:09:58
SQL> select group_number,name from v$asm_diskgroup;
GROUP_NUMBER NAME
------------ ------------------------------
1 DATA
2 FLASH
0 DGNEW
ANALYSIS :
Following is done on some Test server. It is higly recommended to understand the impact before performing such actions on customer systems. Dismounting of Diskgroups are not to be done while they are being used by some db instances !!!!!!
SQL> select group_number, name, state, type from v$asm_diskgroup;
GROUP_NUMBER NAME STATE TYPE
------------ ------------------------------ ----------- ------
1 DATA MOUNTED NORMAL
2 FLASH MOUNTED EXTERN
0 DGNEW DISMOUNTED
SQL> alter diskgroup data dismount;
Diskgroup altered.
SQL> alter diskgroup flash dismount;
Diskgroup altered.
SQL> alter diskgroup dgnew dismount;
Diskgroup altered.
SQL> select group_number, name, state, type from v$asm_diskgroup;
GROUP_NUMBER NAME STATE TYPE
------------ ------------------------------ ----------- ------
0 DGNEW DISMOUNTED
0 FLASH DISMOUNTED
0 DATA DISMOUNTED
Whenever you see the group_number 0 that means it is not mounted.