Add and drop disk at the same time in ASM

Adding and dropping some disks at the some time in ASM

sqlplus "/as sysasm"

set lines 200

set pages 1000

col path format a36

col name format a22

col failgroup format a20

col label format a15

col type format a15

col header_status format a20

To see information about disk 

select GROUP_NUMBER,DISK_NUMBER,PATH,NAME,FAILGROUP,MOUNT_STATUS,HEADER_STATUS,STATE,TOTAL_MB,FREE_MB from v$asm_disk;

select GROUP_NUMBER,NAME,BLOCK_SIZE,STATE,TYPE,TOTAL_MB,FREE_MB,USABLE_FILE_MB,REQUIRED_MIRROR_FREE_MB,OFFLINE_DISKS,COMPATIBILITY, DATABASE_COMPATIBILITY from v$asm_diskgroup;

To see only candidate disk

column path format  a40

Select PATH,GROUP_NUMBER,DISK_NUMBER,MOUNT_Status, HEADER_STATUS, TOTAL_MB, create_date

  from v$asm_disk

where header_status='CANDIDATE'

order by path;

To add and drop disk at the same time
ALTER DISKGROUP data
ADD DISK '/dev/sdg1','/dev/sdh1' 
DROP DISK 'DATA_0003','DATA_0004' 
REBALANCE POWER 3;

to monitor rebalance operation 
select * from v$asm_operation;

or

#asmcmd
asmcmd> lsop

or

#asmcmd lsop