Oracle ASM Commands

col PATH form a25
col GB_read for 99999
col GB_written for 9999

select a.PATH, a.mount_status, a.state, a.TOTAL_MB, a.FREE_MB, a.mount_date, a.bytes_read/1024/1024/1024 GB_read, 
a.BYTES_WRITTEN/1024/1024/1024 GB_written, dg.name AS DISK_GROUP
from v$asm_disk_stat a, V$ASM_DISKGROUP dg
WHERE dg.group_number = a.group_number
order by disk_group
/

PATH                      MOUNT_S STATE      TOTAL_MB    FREE_MB MOUNT_DAT GB_READ GB_WRITTEN DISK_GROUP
------------------------- ------- -------- ---------- ---------- --------- ------- ---------- ----------
ORCL:ASM252_VMAX0050F     CACHED  NORMAL       246246      23607 25-AUG-14       6         13 MY_DATA
ORCL:ASM252_VMAX00510     CACHED  NORMAL       246246      23616 25-AUG-14       6         13 MY_DATA
ORCL:ASM252_VMAX01C82     CACHED  NORMAL       246246      60811 25-AUG-14      39         11 MY_RECOVERY
ORCL:ASM252_VMAX01C83     CACHED  NORMAL       246246      60808 25-AUG-14      40         11 MY_RECOVERY

set pages 50000 lines 100 echo on head on flush on veri on feed on
col INSTANCE_NAME form a20
col SOFTWARE_VERSION form a20
col COMPATIBLE_VERSION form a20

select * from v$asm_client;

GROUP_NUMBER INSTANCE_NAME        DB_NAME  STATUS       SOFTWARE_VERSION     COMPATIBLE_VERSION
------------ -------------------- -------- ------------ -------------------- --------------------
           1 +ASM1                mylxtdb  CONNECTED    11.1.0.7.0           11.0.0.0.0
           2 +ASM1                mylxtdb  CONNECTED    11.1.0.7.0           11.0.0.0.0

select DISK_NUMBER,MOUNT_STATUS,HEADER_STATUS,MODE_STATUS,STATE,PATH,TOTAL_MB from gv$asm_disk;

DISK_NUMBER MOUNT_S HEADER_STATU MODE_ST STATE    PATH                             TOTAL_MB
----------- ------- ------------ ------- -------- ------------------------------ ----------
          2 CACHED  MEMBER       ONLINE  NORMAL   ORCL:ASM252_VMAX0050F              246246
          3 CACHED  MEMBER       ONLINE  NORMAL   ORCL:ASM252_VMAX00510              246246
          0 CACHED  MEMBER       ONLINE  NORMAL   ORCL:ASM252_VMAX01C82              246246

SELECT SUBSTR(d.name,1,16) AS asmdisk,PATH, dg.name AS diskgroup 
FROM V$ASM_DISKGROUP dg, V$ASM_DISK d 
WHERE dg.group_number = d.group_number 
and dg.name in ('MY_DATA','MY_RECOVERY') order by dg.name ;

ASMDISK          PATH                                     DISKGROUP
---------------- ---------------------------------------- ---------------------
ASM252_VMAX01C83 ORCL:ASM252_VMAX01C83                    MY_DATA
ASM252_VMAX01F67 ORCL:ASM252_VMAX01F67                    MY_DATA
ASM252_VMAX01C85 ORCL:ASM252_VMAX01C85                    MY_RECOVERY
ASM252_VMAX01C84 ORCL:ASM252_VMAX01C84                    MY_RECOVERY

Identify the Disks you want to add and Disks you want to remove by using "oracleasm listdisks" as oracle user on the server.
The below command would add the disks you want to add and remove the older (existing disks) and do the re-balance. You can set
the rebalance power from 1 to 11. 11 would use more resources and would be the fastest way to rebalance.
NOTE: When adding Disk(s), you have to prefix the device name with "ORCL:"

alter diskgroup MY_DATA
 add disk
  'ORCL:ASM176_VMAX02049',
  'ORCL:ASM176_VMAX0204A'
 drop disk
  'ASM252_VMAX01F67',
  'ASM252_VMAX01C82',
rebalance power 11 ;

Check the rebalance progress using the below script.

select sysdate, GROUP_NUMBER, OPERATION, STATE, POWER, ACTUAL, SOFAR, EST_WORK, EST_RATE, EST_MINUTES
from v$asm_operation;