How to create an ASM diskgroup

Create ASM Disk Group

Step1:

Set ASM Environment and Login to your ASM instance as sysasm

[oracle@node2 ~]$ export ORACLE_HOME=/u01/app/12.2.0.2/grid
[oracle@node2 ~]$ export PATH=$PATH:$ORACLE_HOME/bin
[oracle@node2 ~]$ export ORACLE_SID=+ASM2
[oracle@node2 ~]$ sqlplus "/as sysasm"

Step2:

Identify the availiable Candidate/Provisioned disks

set line 200
col path for a50
select MOUNT_STATUS,HEADER_STATUS,STATE,PATH from v$asm_disk

MOUNT_S HEADER_STATU STATE    PATH
------- ------------ -------- ------------------------------------------------------------
CLOSED  PROVISIONED  NORMAL   /dev/oracleasm/disks/DISK5
CLOSED  PROVISIONED  NORMAL   /dev/oracleasm/disks/DISK6
CLOSED  PROVISIONED  NORMAL   /dev/oracleasm/disks/DISK8
CLOSED  PROVISIONED  NORMAL   /dev/oracleasm/disks/DISK7CACHED  MEMBER       NORMAL   /dev/oracleasm/disks/DISK4
CACHED  MEMBER       NORMAL   /dev/oracleasm/disks/DISK3
CACHED  MEMBER       NORMAL   /dev/oracleasm/disks/DISK2
CACHED  MEMBER       NORMAL   /dev/oracleasm/disks/DISK1

8 rows selected.

Step3:

create diskgroup DATA normal redundancy FAILGROUP FG1 disk '/dev/oracleasm/disks/DISK5' FAILGROUP FG2 disk '/dev/oracleasm/disks/DISK6';

Diskgroup created.

Note:- if you are creating diskgroup on RAC ensure the diskgroup is mounted on 2nd node. If it is not mounted you must mount it.

select INST_ID,NAME,STATE from gv$asm_diskgroup;

   INST_ID NAME                           STATE
---------- ------------------------------ -----------
         1 DATA_MGMT                      MOUNTED
         1 OCR_VOT                        MOUNTED
         1 DATA                           MOUNTED
         2 DATA                           DISMOUNTED
         2 DATA_MGMT                      MOUNTED
         2 OCR_VOT                        MOUNTED

6 rows selected.

SQL> alter diskgroup DATA mount;

Diskgroup altered.

SQL> select INST_ID,NAME,STATE from gv$asm_diskgroup;

   INST_ID NAME                           STATE
---------- ------------------------------ -----------
         1 DATA_MGMT                      MOUNTED
         1 OCR_VOT                        MOUNTED
         1 DATA                           MOUNTED
         2 DATA_MGMT                      MOUNTED
         2 OCR_VOT                        MOUNTED
         2 DATA                           MOUNTED

6 rows selected.

How to Change the Compatible Attribute of ASM Diskgroup

ALTER DISKGROUP DATA SET ATTRIBUTE 'compatible.asm' = '12.1';

Diskgroup altered.

ALTER DISKGROUP DATA SET ATTRIBUTE 'compatible.rdbms' = '12.1';

Diskgroup altered.