4 Replies Latest reply: Jun 13, 2014 9:31 AM by Levi Pereira RSS

    Question of finding about which disk belongs to which storage


      Dear system administrators,


      I am struggling with finding about which disk belongs to which storage. And also, I have a problem with knowing that which physical disk is related to which Worl Wide Name. The reason I need to know is I am in the process of building oracle RAC and need to provide redundancy well. Because my oracle database should be still alive when one of storage device goes offline. Here is what I want:


      |     partition number      |      disk name   |    disk size   |   storage number     |


      So could you please share us your experience on this matter.


      Thank you,

        • 1. Re: Question of finding about which disk belongs to which storage

          I would not partition a disk for ASM storage, unless there are very exceptional circumstances.


          As for your report - you can do this using ASM and SQL. ASM tells you the disk name (o/s device), the ASM disk name, the diskgroup it belongs to, and the amount of (usable) space on that disk, and so on.


          As for partition numbering - on Linux the p<n> suffix is used for disks. E.g. /dev/sdbp2 is partition 2 on /dev/sdb.


          Of course, using multipath makes this a lot easier - as each server node will use the SAME logical device name for a SAN/NAS storage disk/LUN, via the WWID of that disk/LUN.


          So no need to list the WWID, unless you want to map the server device to a specific physical device on the SAN.


          The real question is though what exact question or requirement is your report suppose to answer? Want to see disks in use? Which failgroups and diskgroups? Which are spare/candidate disks? ASM tells you all that. And more. If you bother learning the basic meta data layer ASM provides for the storage layer.

          • 2. Re: Question of finding about which disk belongs to which storage


            If you want to obtain that information you need a sysadmin.


            You can check on your Storage administrator interface the information about the WWN and the Disk name that is presented to each server.


            Then you can check on each server the information of each disk and each partition.


            With that information you will be able to create a text/excel File with your Storage configuration for each server (inventory).


            It is important that someone with experience help you if you are designing a production environment.



            • 3. Re: Question of finding about which disk belongs to which storage

              Take this below query output.



              spool asm1.html

              SET MARKUP HTML ON

              set echo on

              set pagesize 200

              alter session set nls_date_format='DD-MON-YYYY HH24:MI:SS';

              select 'THIS ASM REPORT WAS GENERATED AT: ==)> ' , sysdate " " from dual;

              select 'HOSTNAME ASSOCIATED WITH THIS ASM INSTANCE: ==)> ' , MACHINE " " from v$session where program like '%SMON%';

              select * from v$asm_diskgroup;


              SELECT * FROM V$ASM_CLIENT;

              select * from V$ASM_ATTRIBUTE;

              select * from v$asm_operation;

              select * from gv$asm_operation

              select * from v$version;

              show parameter asm

              show parameter cluster

              show parameter instance_type

              show parameter instance_name

              show parameter spfile

              show sga

              spool off



              Note : Run on ASM instance , Up to some extend this will help you in identifying  servers.



              -Arjun B

              • 4. Re: Question of finding about which disk belongs to which storage
                Levi Pereira

                This design is created by SysAdmin or someone which configured your storage. Then as mentioned previously you need a Sysadmin to help you.


                Using default names of devices generated by S.O you have a poor configuration.

                To a better identification and administration I recommend you set up your devices by using UDEV (linux) or MKNOD (aix) creating a name which identify the purpose of that Lun.