Change the redundancy of the Disk Group of the ASM instance

[Former Member]

You want to change the redundancy of the Disk Group of the ASM instance.

Current situation:

If you try to dismount/drop:

Why?
Because the ASM instance has its spfile on it:

[grid@ora-asm:+ASM ~]$ asmcmd

ASMCMD> spget

+DATA/asm/asmparameterfile/registry.253.907250463

How to procede then

Firts, you need to add another diskgroup (VOL3):

[root@ora-asm ~]# oracleasm createdisk VOL3 /dev/sdd1

Writing disk header: done

Instantiating disk: done

[root@ora-asm ~]# oracleasm listdisks

VOL1

VOL2

VOL3

Present the new disk to asm.  

Create a new DG, this time with External redundancy:

asmca

Now we have to move the parameter file from +DATA to +DG_GRID.

Create a pfile from spfile, and shutdown the asm instance:

SQL> create pfile='/tmp/init+ASM.ora' from spfile;

File created.

SQL> shut immediate;

ASM diskgroups dismounted

ASM instance shutdown

Start from pfile:

SQL> startup pfile='/tmp/init+ASM.ora';

ASM instance started

Total System Global Area 1135747072 bytes

Fixed Size                  2260728 bytes

Variable Size 1108320520 bytes

ASM Cache 25165824 bytes

ASM diskgroups mounted

SQL> show parameter spfile

NAME TYPE        VALUE

------------------------------------ ----------- ------------------------------

spfile string

There is no spfile configured.

Now, all we have to do is to create a new spfile in the new location DG_GRID:

SQL> create spfile='+DG_GRID/init.ora' from pfile='/tmp/init+ASM.ora';

File created.

Shutdown and start the instance again, and you can see the spfile created in the new location:

SQL> shut immediate;

ASM diskgroups dismounted

ASM instance shutdown

SQL> startup

ASM instance started

Total System Global Area 1135747072 bytes

Fixed Size 2260728 bytes

Variable Size 1108320520 bytes

ASM Cache 25165824 bytes

ASM diskgroups mounted

SQL> show parameter spfile

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

spfile string      +DG_GRID/init.ora

Now, delete (dismount and drop) the old dg DATA, and thats it, you have changed the redundancy of your DG.

asmca

Regards,

Richard W. L. Brehmer

http://www.rbrehmer.com