Oracle Database check ASM diskgroup and Manage ASM disks

Check the Size and free space in ASM Diskgroup

col name for a10
col percentage 999.99
SELECT name, free_mb, total_mb, free_mb/total_mb*100 as percentage FROM v$asm_diskgroup;

Check the ASM Disk stats

select * from V$ASM_DISK_IOSTAT;

Mount and Dismount ASM Disk group

--Mount the diskgroup

SQL>alter diskgroup DATA mount;

or

asmcmd>mount DATA

--Unmount the diskgroup

SQL>alter diskgroup DATA dismount;

OR

asmcmd>umount DATA

-- To mount/Dismount all the diskgroups

SQL>alter diskgroup ALL mount;
SQL>alter diskgroup ALL dismount;

Drop the ASM Disk

-----Dropping one disk:

alter diskgroup data drop disk DATA01;

-----Dropping multiple disk:

alter diskgroup data drop disk DATA01,DATA02, DATA03 rebalance power 10;

---- Monitoring the rebalance operation:

select * from v$asm_operation;

Monitor the Rebalance operation

select GROUP_NUMBER,OPERATION,STATE,POWER, ACTUAL,ACTUAL,EST_MINUTES from gv$asm_operation;

--Change power of rebalance

alter diskgroup DATA rebalance power 10;

Drop ASM Disgroup

drop diskgroup DATA including contents;

Create ASM Disk in Linux

-- Check the asm disk is used

#/etc/init.d/oracleasm querydisk /dev/sdb1
Device "/dev/sdb1" is not marked as an ASM disk

-- Create asm disk

# /etc/init.d/oracleasm createdisk DATA /dev/sdb1
Marking disk "DATA" as an ASM disk: [ OK ]

-- Check the asm disk labelling

# /etc/init.d/oracleasm querydisk /dev/sdb1
Device "/dev/sdb1" is marked an ASM disk with the label "DATA"

-- List the asm disks present

# /etc/init.d/oracleasm listdisks
DATA

Create Diskgroup in SQLPLUS

CREATE DISKGROUP DATA EXTERNAL REDUNDANCY DISK '/dev/sdb*';