Change the redundancy of the Disk Group of the ASM instance

Posted on Posted in ASM, Oracle Database

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

Current situation:
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If you try to dismount/drop:

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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

 

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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

 

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Regards,
Richard W. L. Brehmer

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