3 Replies Latest reply: Jan 10, 2014 12:41 AM by Rajasekhar Amudala-Oracle RSS

    OCR/Voting Disk on ASM questions

    user8894222

      I've been trying to wrap my head around this topic for the past two days and I can not find a clear answer.

       

      What does this mean?

       

      The number of voting files you can store in a particular Oracle ASM disk group depends upon the redundancy of the disk group.

      • External redundancy: A disk group with external redundancy can store only one voting disk
      • Normal redundancy: A disk group with normal redundancy stores three voting disks
      • High redundancy: A disk group with high redundancy stores five voting disks

       

      That I if +ORAOCR is at high redundancy that it has 5 voting disks which are on 3 disk/devices?

      Or do I need to have 5 disk/devices?

       

      Separate, but related question. When I run ocrcheck does this tell me I only have one voting disk? And thus, I can assume I'm running external redundancy on a single device?

       

      Status of Oracle Cluster Registry is as follows :

               Version                  :          3

               Total space (kbytes)     :     262120

               Used space (kbytes)      :       2964

               Available space (kbytes) :     259156

               ID                       : 1787678286

               Device/File Name         : +ORAOPERD_OCR

                                          Device/File integrity check succeeded

       

       

                                          Device/File not configured

       

       

                                          Device/File not configured

       

       

                                          Device/File not configured

       

       

                                          Device/File not configured

       

      --Mark

        • 1. Re: OCR/Voting Disk on ASM questions
          Hemant K Chitale

          You should look at the diskgroup information (V$ASM_DISKGROUP) for ORAOPERD_OCR  to identify the redundancy.

           

          As for the first question, Oracle uses a different failure group for each voting disk.  A high redundancy disk group has at least 3 failure groups.  Each group may consist of multiple disks.  So it is not the question of "5 disks" but how many failure groups you have.  The voting disks would be distributed amongst the failure groups.

           

           

          Hemant K Chitale

          • 2. Re: OCR/Voting Disk on ASM questions
            Levi Pereira

            > When I run ocrcheck does this tell me I only have one voting disk? And thus, I can assume I'm running external redundancy on a single device?

             

            There is a wrong concept here . OCRCHECK is for OCR only, to see VOTING DISK info you should use following command "crsctl query css votedisk"

             

            Check this out:

            Explaining: How to store OCR, Voting disks and ASM SPFILE on ASM Diskgroup (RAC or RAC Extended) | Levi Pereira | Oracl…

            • 3. Re: OCR/Voting Disk on ASM questions
              Rajasekhar Amudala-Oracle

              Hi,

               

              The output from 11gR2, ocr and vote disk kept ASM diskgroup +DATA >>>>>>>>>>>>It is Normal redundancy. Please check the below in detail

               

              1) ocrcheck command check the integrity of OCR

               

              [root@rac1 ~]# ocrcheck

              Status of Oracle Cluster Registry is as follows :

                       Version                  :          3

                       Total space (kbytes)     :     262120

                       Used space (kbytes)      :       3344

                       Available space (kbytes) :     258776

                       ID                       : 1037097601

                       Device/File Name         :      +DATA                            >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Check the diskgroup type

                                                  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 succeeded

               

               

              [root@rac1 ~]#

               

              2) Login ASM using sqlplus >>>>>>>>>>>>> Check for diskgroup type which is using for OCR/VOTE DISK.

               

               

               

              SQL> select NAME, TYPE from v$asm_diskgroup where name='DATA';

               

               

              NAME                           TYPE

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

              DATA                           NORMAL

               

               

              SQL>



              ##########################################################

              Another example below for External Redundancy


              1)


              [root@host01 ~]# ocrcheck

              Status of Oracle Cluster Registry is as follows :

                       Version                  :          3

                       Total space (kbytes)     :     262120

                       Used space (kbytes)      :       3488

                       Available space (kbytes) :     258632

                       ID                       : 1546379639

                       Device/File Name         :       +OCR

                                                  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 succeeded

               

               

              [root@host01 ~]#

               

               

              2)

               

              SQL> select NAME, TYPE from v$asm_diskgroup where name='OCR';

               

               

              NAME                           TYPE

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

              OCR                            EXTERN

               

               

              SQL>

               

              ##########################################################


              Additional Info for you about OCR/Vote disk redundancy >>>>>>>>>>>>> It's from 11gR2 >>>>>>>>>>>>>>>>>


              External >>>>> 1 disk

              Normal >>>>>> 3 disks

              High >>>>>>>> 5 disks


              ###########################################################


              For ASM >>>>>>>>


              External >>>>> Minimum need 1 disk

              Normal >>>>>> Minimum need 2 disks

              High >>>>>>>> Minimum need 3 disks