Day: December 8, 2023

How to Add a Disk into ASM DiskGroup Safely

For a client, there are situations when adding a disk into ASM disk group failed, finally rebooting the server is required to resolve this issue.

According to Oracle support suggestion, we can create a test diskgroup by using this new disk, if everything is successful, then we can drop this test diskgroup, and add the new disk into target diskgroup.

It is a good practice specially for critical production environment.

Check the new disk is a “CANDIDATE”

$sqlplus / as sysasm 



SQL>select INST_ID,GROUP_NUMBER,DISK_NUMBER,MOUNT_STATUS,HEADER_STATUS,
           MODE_STATUS,STATE,REDUNDANCY,OS_MB,OS_MB,TOTAL_MB,NAME,
           FAILGROUP,PATH 
from gv$asm_disk 
where PATH like '/dev/mapper/prod_data_303p1' 
order by 1,2,3;

Create a Test Diskgroup

Create a test diskgroup “TEMP_TEST”, and check disk status is “MEMBER”

SQL> CREATE DISKGROUP TEMP_TEST EXTERNAL REDUNDANCY disk '/dev/mapper/prod_data_303p1' NAME TEMP_TEST_0001;



Diskgroup created.
SQL>select INST_ID,GROUP_NUMBER,DISK_NUMBER,MOUNT_STATUS,HEADER_STATUS,
           MODE_STATUS,STATE,REDUNDANCY,OS_MB,OS_MB,TOTAL_MB,NAME,
           FAILGROUP,PATH 
from gv$asm_disk 
where PATH like '/dev/mapper/prod_data_303p1' 
order by 1,2,3;

Mount the Test Diskgroup on Other Nodes

Mount the test diskgrop on all the rest ASM nodes to make sure all working fine.

$sqlplus / as sysasm

SQL>set pagesize 100
SQL>set linesize 300
SQL>select INST_ID,GROUP_NUMBER,NAME,STATE,TOTAL_MB,FREE_MB,
           COMPATIBILITY,DATABASE_COMPATIBILITY 
from  gv$asm_diskgroup 
where name='TEMP_TEST' 
order by 1,2;
SQL> alter diskgroup TEMP_TEST mount;



Diskgroup altered.
SQL>select INST_ID,GROUP_NUMBER,NAME,STATE,TOTAL_MB,FREE_MB,
           COMPATIBILITY,DATABASE_COMPATIBILITY 
from  gv$asm_diskgroup 
where name='TEMP_TEST' 
order by 1,2;

Dismount the Test Diskgroup on Other Nodes

Dismount the test diskgroup on all the other nodes except the first node for dropping in the next step.

SQL> alter diskgroup TEMP_TEST dismount;



Diskgroup altered.

SQL>select INST_ID,GROUP_NUMBER,NAME,STATE,TOTAL_MB,FREE_MB,
           COMPATIBILITY,DATABASE_COMPATIBILITY 
from  gv$asm_diskgroup 
where name='TEMP_TEST' 
order by 1,2;

Drop the Test Diskgroup

Drop the test diskgroup on first node where the test diskgroup is still mounted.

SQL> DROP DISKGROUP  TEMP_TEST ;



Diskgroup dropped.

And check the new disk header status is “FORMER”, which is available for adding into target diskgroup now.

SQL>select INST_ID,GROUP_NUMBER,DISK_NUMBER,MOUNT_STATUS,HEADER_STATUS,
           MODE_STATUS,STATE,REDUNDANCY,OS_MB,OS_MB,TOTAL_MB,NAME,
           FAILGROUP,PATH 
from gv$asm_disk 
where PATH like '/dev/mapper/prod_data_303p1' 
order by 1,2,3;

Add Disk into Target Diskgroup

Now it is time to add the new disk into target diskgroup.

SQL> set time on

08:08:17 SQL> ALTER DISKGROUP PROD_DATA ADD DISK '/dev/mapper/prod_data_303p1' NAME PROD_DATA_0012;



Diskgroup altered.

Then check disk and diskgroup status

09:09:01 SQL>select INST_ID,GROUP_NUMBER,DISK_NUMBER,MOUNT_STATUS,
                    HEADER_STATUS,MODE_STATUS,STATE,REDUNDANCY,
                    OS_MB,OS_MB,TOTAL_MB,NAME,FAILGROUP,PATH 
from gv$asm_disk 
where PATH like '%prod_data%' 
order by 1,2,3;
09:09:14 SQL>  select INST_ID,GROUP_NUMBER,NAME,STATE,TOTAL_MB,FREE_MB,
                      COMPATIBILITY,DATABASE_COMPATIBILITY 
from  gv$asm_diskgroup 
where name='PROD_DATA' ;

Monitor and Check Rebalance

00:10:35 SQL> select GROUP_NUMBER,OPERATION,STATE,POWER,ACTUAL,
                     SOFAR,EST_WORK,EST_RATE,EST_MINUTES 
              from   v$asm_operation;