Oracle Database - 18c - RAC 18c Disk Group Creation

In this blog, I am going to talk about Disk Group Creation in RAC 18c.

First I am going to create the disks at the OS level and discover it in oracleasm. 



1. Create Partition for New Disks. Do this for all the disks you have attached to your system. Make sure disks are attached to both nodes and partition is created on only one Node. 
Details on Creating the partition are present in end of the blog.

2.  Create Disks using oracleasm on Node 1

[root@rac18c01 tmp]# oracleasm createdisk DATA1 /dev/xvdf1
Writing disk header: done
Instantiating disk: done

[root@rac18c01 tmp]# oracleasm createdisk DATA2 /dev/xvdg1
Writing disk header: done
Instantiating disk: done


[root@rac18c01 tmp]# oracleasm createdisk DATA3 /dev/xvdh1
Writing disk header: done
Instantiating disk: done

3.  Scan for disks using oracleasm on Node 2
[root@rac18c02 ~]# oracleasm scandisks
Reloading disk partitions: done
Cleaning any stale ASM disks...
Scanning system for ASM disks...
Instantiating disk "DATA1"
Instantiating disk "DATA2"

Instantiating disk "DATA3"

4. Login as Grid and set the environment run asmca 
[grid@rac18c01 grid]$ . oraenv
ORACLE_SID = [grid] ? -MGMTDB
The Oracle base has been set to /u01/app/grid

[grid@rac18c01 grid]$ asmca

1. Click on Create

2. Set the Disk Group Name to 'DATA'

3. Select the available disks (if required change the discovery path as below)

4. Click on Advanced Options and set compatibility parameter if required.

5. Finally Click OK

New Disk Group has been created on the system.



New Disk Partition Creation 
[root@rac18c01 tmp]# fdisk /dev/xvdf
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xc0515184.

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-251658239, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-251658239, default 251658239):
Using default value 251658239
Partition 1 of type Linux and of size 120 GiB is set

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.