EXADATA: How to resize ASM disks

EXADATA: How to resize ASM disks

Requirement:
Reduce the space allocated to RECO Diskgroup and allocate the space to DATA diskgroup.
Exclusion:
No change in redundacy at any level.
No add or drop any griddisk.
Approach:
1.Check the free space in celldisk and griddisk of both DATA and RECO
2.resize the RECO diskgroup
3.resize (reduction) griddisk of RECO diskgroup
4.resize (addition) griddisk of DATA diskgroup
5.resize the DATA diskgroup.
6.Check the free space 
7.conclude
Steps:
1.Login to storage cell and check

# cellcli -e "list celldisk where name like 'CD.*' attributes name, size, freespace"

# cellcli -e "list griddisk where name like 'DATA.*' attributes name, size"
# cellcli -e "list griddisk where name like 'RECO.*' attributes name, size"

2. Login to ASM instance in compute node

$ sqlplus / as sysasm
SQL> alter diskgroup RECO resize all size 20000M rebalance power 32;
SQL> select name, total_mb from v$asm_disk_stat where name like 'RECO%';

3. Login to *ALL* Storage cell and resize for RECO
# cellcli -e alter griddisk RECO_CD_00_exacell01, RECO_CD_01_exacell01, RECO_CD_02_exacell01, RECO_CD_03_exacell01, RECO_CD_04_exacell01, RECO_CD_05_exacell01, RECO_CD_06_exacell01, RECO_CD_07_exacell01, RECO_CD_08_exacell01, RECO_CD_09_exacell01, RECO_CD_10_exacell01, RECO_CD_11_exacell01 size=234176M;

4. Login to *ALL* Storage cell and resize for DATA
# cellcli -e alter griddisk DATA_CD_00_exacell01, DATA_CD_01_exacell01, DATA_CD_02_exacell01, DATA_CD_03_exacell01, DATA_CD_04_exacell01, DATA_CD_05_exacell01, DATA_CD_06_exacell01, DATA_CD_07_exacell01, DATA_CD_08_exacell01, DATA_CD_09_exacell01, DATA_CD_10_exacell01, DATA_CD_11_exacell01 size=300G;

5. Login to ASM instance in compute node and resize grid disk for DATA 

$ sqlplus / as sysasm
SQL> alter diskgroup DATA resize all rebalance power 32;

6. check free space
SQL> select name, total_mb/1024 "GB" from v$asm_disk_stat where name like 'DATA%';