4 Replies Latest reply: May 20, 2013 10:35 AM by AshishShukla RSS

    OCR Redundancy - Can we have OCR Mirror with Redo logs in REDO01 diskgroup?

    Azam
      Hello,

      I have 2 node Oracle 11gr2 (11.2.0.3) RAC on AIX 6.1. Currently there is only one OCR and one VD residing in OCRVD diskgroup which as external redundancy.

      ## STATE File Universal Id File Name Disk group
      -- ----- ----------------- --------- ---------
      1. ONLINE a27d6a5df2db4f31bf0c9c9d31870b1f (/dev/rhdisk11) [OCRVD]
      Located 1 voting disk(s).


      $ ocrcheck
      Status of Oracle Cluster Registry is as follows :
      Version : 3
      Total space (kbytes) : 262120
      Used space (kbytes) : 3152
      Available space (kbytes) : 258968
      ID : 899322289
      Device/File Name : +OCRVD
      Device/File integrity check succeeded

      Device/File not configured

      Device/File not configured

      Device/File not configured

      Device/File not configured

      Cluster registry integrity check succeeded

      Logical corruption check bypassed due to non-privileged user

      OCRVD Diskgroup is created using 5 disks of size 1G with RAID 1.

      1. Is it possible that I multiplex OCR and VD in the same diskgroup?
      2. If it is not possible, then shall I add OCR and VD in other diskgroups (Eg: REDO01 and REDO02 - these are for Redo logs)?

      Edited by: Azam on May 20, 2013 2:46 PM
        • 1. Re: OCR Redundancy - Can we have OCR Mirror with Redo logs in REDO01 diskgroup?
          Mahir M. Quluzade
          Azam wrote:
          Hello,

          I have 2 node Oracle 11gr2 (11.2.0.3) RAC on AIX 6.1. Currently there is only one OCR and one VD residing in OCRVD diskgroup which as external redundancy.

          ## STATE File Universal Id File Name Disk group
          -- ----- ----------------- --------- ---------
          1. ONLINE a27d6a5df2db4f31bf0c9c9d31870b1f (/dev/rhdisk11) [OCRVD]
          Located 1 voting disk(s).


          $ ocrcheck
          Status of Oracle Cluster Registry is as follows :
          Version : 3
          Total space (kbytes) : 262120
          Used space (kbytes) : 3152
          Available space (kbytes) : 258968
          ID : 899322289
          Device/File Name : +OCRVD
          Device/File integrity check succeeded

          Device/File not configured

          Device/File not configured

          Device/File not configured

          Device/File not configured

          Cluster registry integrity check succeeded

          Logical corruption check bypassed due to non-privileged user

          OCRVD Diskgroup is created using 5 disks of size 1G with RAID 1.

          1. Is it possible that I multiplex OCR and VD in the same diskgroup?
          No, it is no posible
          2. If it is not possible, then shall I add OCR and VD in other diskgroups (Eg: REDO01 and REDO02 - these are for Redo logs)?
          Yes you can add other diskgroups. As the root user, run the following command to add an OCR location to either Oracle ASM
          ocrconfig -add +REDO01
          ocrconfig -add +REDO02
          As you know mirroring on ASM level between ASM disks which is contains in ASM DISKGROUP.


          Regards
          Mahir M. Quluzade
          • 2. Re: OCR Redundancy - Can we have OCR Mirror with Redo logs in REDO01 diskgroup?
            rarain
            Hi,

            With OCR you can also move voting disk from one diskgroup to another diskgroup online and based on the redundancy of the diskgroup number of voting disks will be configured.

            # crsctl replace votedisk <+DISKGROUP_NAME>

            External-> one voting disk
            Normal -> Three voting disk
            High -> Five Voting disk

            Thanks
            • 3. Re: OCR Redundancy - Can we have OCR Mirror with Redo logs in REDO01 diskgroup?
              Mahir M. Quluzade
              rarain wrote:
              Hi,

              With OCR you can also move voting disk from one diskgroup to another diskgroup online and based on the redundancy of the diskgroup number of voting disks will be configured.

              # crsctl replace votedisk <+DISKGROUP_NAME>

              External-> one voting disk
              Normal -> Three voting disk
              High -> Five Voting disk

              Thanks
              Oracle recommended : High Redundancy disk groups for OCR and VOTE disk. Only for OCR Normal Redundancy must be with 3 and High is must be 5 Fail group.
              If you are using disk groups for normal data (non OCR). Normal redundancy 2 way mirroring, and High redundancy is 3 way mirroring.

              Regards
              Mahir M. Quluzade
              • 4. Re: OCR Redundancy - Can we have OCR Mirror with Redo logs in REDO01 diskgroup?
                AshishShukla
                Hello Azam,


                First of all answer for your question is YES.

                One of the new feature of 11.2 RAC is, now we can store OCR & VOTING disk both on ASM. Even if you want you can store both OCR & Voting disk on the same diskgroup.

                Please not that ASM does striping for OCR file but it keeps voting file as it is without doing striping.
                In my case My OCR & VOTING disks are on +DATA diskgroup.

                [grid@host01 ~]$ crsctl query css votedisk

                ## STATE File Universal Id File Name Disk group
                -- ----- ----------------- --------- ---------
                1. ONLINE 43b81ce42d9d4f9bbfcc3914003d5ac9 (ORCL:ASMDISK01) *[DATA]*
                2. ONLINE 38e71bedf4174f24bfa7ee6ab48ef858 (ORCL:ASMDISK02) *[DATA]*
                3. ONLINE 026cb26c84424f49bf130480562ab3f1 (ORCL:ASMDISK03) *[DATA]*
                Located 3 voting disk(s).

                [root@host01 ~]# ocrcheck
                Status of Oracle Cluster Registry is as follows :
                Version : 3
                Total space (kbytes) : 262120
                Used space (kbytes) : 3584
                Available space (kbytes) : 258536
                ID : 456262459
                Device/File Name : +DATA*

                ASM does striping for OCR that you can verify from this output:

                ASMCMD> lstmpl -G DATA -l
                Group_Name Group_Num Name      Stripe           Sys Redund      PriReg MirrReg
                DATA 2 ARCHIVELOG           COARSE      Y MIRROR      COLD COLD
                DATA 2 ASMPARAMETERBAKFILE      COARSE      Y MIRROR      COLD COLD
                DATA 2 ASMPARAMETERFILE      COARSE      Y MIRROR      COLD COLD
                DATA 2 ASM_STALE           COARSE      Y HIGH      COLD COLD
                DATA 2 AUTOBACKUP           COARSE      Y MIRROR      COLD COLD
                DATA 2 BACKUPSET           COARSE      Y MIRROR      COLD COLD
                DATA 2 CHANGETRACKING      COARSE      Y MIRROR      COLD COLD
                DATA 2 CONTROLFILE      FINE      Y HIGH      COLD COLD
                DATA 2 DATAFILE           COARSE      Y MIRROR      COLD COLD
                DATA 2 DATAGUARDCONFIG      COARSE      Y MIRROR      COLD COLD
                DATA 2 DUMPSET           COARSE      Y MIRROR      COLD COLD
                DATA 2 FLASHBACK           COARSE      Y MIRROR      COLD COLD
                DATA 2 FLASHFILE           COARSE      Y MIRROR      COLD COLD
                DATA 2 OCRBACKUP           COARSE      Y MIRROR      COLD COLD
                DATA        2          OCRFILE                        COARSE       Y    MIRROR       COLD    COLD
                DATA 2 ONLINELOG           COARSE      Y MIRROR      COLD COLD
                DATA 2 PARAMETERFILE      COARSE      Y MIRROR      COLD COLD
                DATA 2 TEMPFILE           COARSE      Y MIRROR      COLD COLD
                DATA 2 XTRANSPORT      COARSE      Y MIRROR      COLD COLD


                Even if you want you can store OCR in one diskgroup and VOTING in another diskgroup. But remember if you are planning to store VOTING disk on any ASM diskgroup then number VOTING disk depend on the redundancy level of the ASM diskgroup.
                e.g:
                diskgroup with,
                External Redundancy     :      One VOTING DISK
                Normal Redundancy     :      Three VOTING DISKS
                High Redundancy     :      Five VOTING DISKS

                Now if you want to move your OCR disks to any other diskgroup, then:

                [root@host01 ~]# *ocrconfig -add +TEST*

                [root@host01 ~]# ocrcheck
                Status of Oracle Cluster Registry is as follows :
                Version : 3
                Total space (kbytes) : 262120
                Used space (kbytes) : 3584
                Available space (kbytes) : 258536
                ID : 456262459
                *Device/File Name         :      +DATA*
                Device/File integrity check succeeded
                *Device/File Name         :      +TEST*
                Device/File integrity check succeeded


                [root@host01 ~]# *ocrconfig -delete +DATA*
                [root@host01 ~]# ocrcheck
                Status of Oracle Cluster Registry is as follows :
                Version : 3
                Total space (kbytes) : 262120
                Used space (kbytes) : 3584
                Available space (kbytes) : 258536
                ID : 456262459
                *Device/File Name         :      +TEST*
                Device/File integrity check succeeded




                Thanks,
                Ashish Shukla