Changing Disk group redundancy

76425c46-a19e-4509-b28d-b5c0fbb0b433

    Hi All,

    I have my OCR disk group set to External Redundancy. I want to change it to Normal Redundancy. Can I know the steps to do this?

      • 1. Re: Changing Disk group redundancy
        Lakmal Rajapakse

        I don't think you can. You will have to create a new disk group with the desired redundancy level.

        • 2. Re: Changing Disk group redundancy
          FreddieEssex

          Hi,

           

          If you only have OCR on the diskgroup then you can check this Metalink note to move your OCR:

           

          OCR / Vote disk Maintenance Operations: (ADD/REMOVE/REPLACE/MOVE) (Doc ID 428681.1)

           

          If you have the database on the diskgroup then there is no easy way of doing this.  Backup/restore your database:

           

          How To Move The Database To Different Diskgroup (Change Diskgroup Redundancy) (Doc ID 438580.1)

          • 3. Re: Changing Disk group redundancy
            Dude!

            You cannot modify the redundancy level of a disk group once it has been created. It is mentioned in the documentation. You can only backup your data and create a new disk group or move the data to another disk group.

            • 4. Re: Changing Disk group redundancy
              76425c46-a19e-4509-b28d-b5c0fbb0b433

              Thanks!

              Say I move from external redundancy +OCRVOTE diskgroup to normal redundancy +CRS diskgroup. And then I drop the diskgroup +OCRVOTE, and recreate it with normal redundancy. And then move from _CRS to +OCRVOTE. Is that possible?


              Step 1: Create diskgroup +CRS with normal redundancy

              Step 2: Move from the diskgroup +OCRVOTE which is with external redundancy to +CRS diskgroup

              Step 3: Drop the diskgroup +OCRVOTE

              Step 4: Recreate the diskgroup +OCRVOTE with normal redundancy

              Step 5: Move from the diskgroup +CRS to +OCRVOTE


              Are these steps ok?

              • 5. Re: Changing Disk group redundancy
                FreddieEssex

                Hi,

                 

                As per the Oracle Note you need at least 2 OCR to use the replace command, and from you say you only have the one OCR.

                • 6. Re: Changing Disk group redundancy
                  Javier Francisco Ruiz

                  These steps will work these are the same steps I took took to move the OCR to a normal redundancy disk group. One thing you need to check is where the spfile of the ASM instance is located if you are using the spfile. Normally the spfile for the ASM instance is create in the same diskgroup were the OCR is created.

                   

                  Below are my steps

                   

                  as root

                  /oragridbase/product/11.2.0/grid/bin/ocrconfig -showbackup

                  /oragridbase/product/11.2.0/grid/bin/ocrcheck

                  /oragridbase/product/11.2.0/grid/bin/ocrconfig -add +DG_OCR_VOTEDISK

                  /oragridbase/product/11.2.0/grid/bin/ocrcheck

                  /oragridbase/product/11.2.0/grid/bin/ocrconfig -delete +DG_OCR_VOTE

                  /oragridbase/product/11.2.0/grid/bin/ocrcheck

                   

                  If you are moving your OCR to normal redundancy diskgroup you should do the same for your vote as well.

                  • 8. Re: Changing Disk group redundancy
                    76425c46-a19e-4509-b28d-b5c0fbb0b433

                    Hi Freddie,

                    I have two diskgroups here, my current one with External redundancy +OCRVOTE and my new diskgroup +CRS with normal redundancy.

                    So in that case, are my above steps correct?

                    • 9. Re: Changing Disk group redundancy
                      Javier Francisco Ruiz

                      You need to look at the other replies in your post. One thing you need to make sure your vote disk are not in the same diakgroup you are planning to recreate is so you need to move the vote as well. Look at the reply Levi posted.

                      • 10. Re: Changing Disk group redundancy
                        76425c46-a19e-4509-b28d-b5c0fbb0b433

                        Hi Javier,

                        In your steps above, I believe the diskgroup DG_OCR_VOTE is of normal redundancy.

                        After your steps above, I would like to re-create the diskgroup DG_OCR_VOTEDISK with normal redundancy and assign it back, Is it ok?

                        • 11. Re: Changing Disk group redundancy
                          Javier Francisco Ruiz

                          Yes it is OK but you need to make sure the VOTE and the ASM instance SPFILE is not in the same existing diskgroup that you want to drop and recreate. It does not matter the redundancy type for the diskgroup you are moving to for the OCR or the SPFILE. Below is the complete steps I took to move my OCR, VOTE and SPFILE to a normal redundancy diskgroup. I would check where you have the vote by executing crsctl query css votedisk. To check the spfile for the asm instance login to the asm instance and do show parameter spfile.

                           

                          --Note: all this is done online

                          /oragridbase/product/11.2.0/grid/bin/ocrconfig -showbackup

                          /oragridbase/product/11.2.0/grid/bin/ocrcheck

                          /oragridbase/product/11.2.0/grid/bin/ocrconfig -add +DG_OCR_VOTEDISK

                          /oragridbase/product/11.2.0/grid/bin/ocrcheck

                          /oragridbase/product/11.2.0/grid/bin/ocrconfig -delete +DG_OCR_VOTE

                          /oragridbase/product/11.2.0/grid/bin/ocrcheck

                           

                          --Note: all this is done online

                          --Move vote with Normal redundancy you need at least 3 failover groups for the vote

                          /oragridbase/product/11.2.0/grid/bin/crsctl query css votedisk

                          /oragridbase/product/11.2.0/grid/bin/crsctl replace votedisk +DG_OCR_VOTEDISK

                          /oragridbase/product/11.2.0/grid/bin/crsctl query css votedisk

                           

                          --recheck the vote and CRS

                          /oragridbase/product/11.2.0/grid/bin/crsctl query css votedisk

                          /oragridbase/product/11.2.0/grid/bin/ocrcheck

                           

                          --Note this will require and outage to move the spfile. This outage can be rolling.

                          --Move asm spfile

                          logon to asm and check the spfile location

                          create pfile='/home/oracle/init+asm.ora' from spfile='+DG_OCR_VOTE/crs_ecomprd/asmparameterfile/registry.253.740765113';

                          shutdown abort the asm instance on each node you can do this one a time to not have a complete outage

                          startup the asm instance with pfile='/home/oracle/init+asm.ora'

                          create spfile='+DG_OCR_VOTEDISK' from pfile='/home/oracle/init+asm.ora';

                          then restart both asm instances