Create a new Diskgroup in ASM

Instance: ASM Instance.
Privilege: Sysdba
Pre-requisite: Disks must be formatted. The path of the disk must be in the ASM_DISKSTRING. Oracle DB user must have read/write permission on the disk.

Syntax:

CREATE DISKGROUP diskgroup_name redundancy_level REDUNDANCY [FAILGROUP failgroup_name]DISK disk_clause

Where,
redundancy_level = HIGH or NORMAL or EXTERNAL
disk_clause = search_string [NAME disk_name] [SIZE size_clause] [FORCE/NOFORCE]

Force – Add disk to the diskgroup even if the disk is part of some other diskgroup.
NoForce – ASM returns error if the disk is part of some other diskgroup.

Example 1

CREATE DISKGROUP asm_data
NORMAL REDUNDANCY
FAILGROUP ctrl_1
DISK
'/u01/asmdisks/disk1' NAME data_01 NOFORCE
,'/u01/asmdisks/disk2' NAME data_02 NOFORCE
FAILGROUP ctrl_2
DISK
'/u03/asmdisks/disk3' NAME data_3 NOFORCE
,'/u03/asmdisks/disk4' NAME data_4 NOFORCE;

If the size clause is omitted the full disk is assigned.

Example 2

SQL> CREATE DISKGROUP ASMIND External REDUNDANCY DISK
'/dev/rhdisk6' SIZE 51200M ,
'/dev/rhdisk7' SIZE 51200M ,
'/dev/rhdisk8' SIZE 51200M ;

If the name clause is omitted the disks are given a system generated name.

Thanks