7 Replies Latest reply: May 21, 2013 6:23 AM by Dude! RSS

    ASM redundancy

    1009889
      Hi,

      My comp is running with RAC 11gR2 with ASM on external redundancy. we are planning to move on normal redundancy.

      which will be better normal redundancy or external redundancy.



      Regards,
      Mak
        • 1. Re: ASM redundancy
          Dude!
          Normal or high redundancy.
          • 2. Re: ASM redundancy
            Renjith Madhavan
            Well the answer depends on your requirement .
            If you have hardware level mirroring ( RAID ) in place then its better to go for external redundancy .

            else

            Go for either NORMAL or HIGH redundancy .


            Thanks
            Renjith Madhavan
            • 3. Re: ASM redundancy
              Mahir M. Quluzade
              Hi,
              1006886 wrote:
              Hi,

              My comp is running with RAC 11gR2 with ASM on external redundancy. we are planning to move on normal redundancy.
              "My comp" Is it means PC ? If yes, then I think you are using Desktop Virtualization tools for implementation Oracle RAC.
              There have not any mirroring on shared virtual disks. Then it is better use Normal redundancy for your ASM Diskgroups.

              >

              Did you have RAID on your Storage?
              If yes, then not need mirroring on ASM disk, because mirroring is better on hardware.
              which will be better normal redundancy or external redundancy.
              It is depend your storage configuration, if not any RAID, then you must use Normal or High redundancy for yoir ASM Disk groups.

              Regards
              Mahir M. Quluzade
              http://www.mahir-quluzade.com
              • 4. Re: ASM redundancy
                1009889
                Dear Mahir M. Quluzade,

                its my company.

                Regards,
                MAK
                • 5. Re: ASM redundancy
                  1009889
                  1st do oracle support all of the redundancy or not.
                  2nd ASM redundancy is a matured enough in recovering.


                  Regards,
                  MAK
                  • 6. Re: ASM redundancy
                    Mahir M. Quluzade
                    It is good, I think you are using storage with RAID (some time RAID 1+0). Then you not need normal or high redundanc,
                    Because have mirroring on hardware layer.

                    Mahir
                    • 7. Re: ASM redundancy
                      Dude!
                      ASM is not RAID. To say that you do not benefit from ASM if your storage is already mirroring data is wrong.

                      ASM is a software based implementation to provide data redundancy, but it is not RAID and works on the basis of file extents (AU units) distributed on available free space of disk failure groups. It knows about Oracle database files and uses an optimal stripping size based on file templates.

                      ASM, unlike RAID solutions provides more configuration and space management flexibility. For instance you can add disks without having to rebuild your RAID configuration. From a performance, redundancy and space utilization aspect, multiple ASM failure groups (single or multiple disks) can provide a better value for money than any RAID solution when using Oracle Database products.

                      ASM is a complementary product and may use devices that are a hardware RAID for additional performance and disk level redundancy. So is ASM with redundancy better than external redundancy: YES.