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4 Replies Latest reply: Dec 11, 2012 9:51 AM by Levi-Pereira RSS

Control file multiplexed RAID question

User477708-OC Journeyer
Currently Being Moderated
2 node RAC. OEL 5. 11.2.0.2

Is there any cause for concern over design issues when placing multiplexed controlfiles on disks with different RAID types?

I have FRA, REDO, VOTE and DATA disk groups available to me DATA is RAID 5, the rest are RAID 10. Is there any tales from the field of write speed issues multiplexing the files on a RAID 5 and a RAID 10?

Edited by: 961469 on Dec 11, 2012 6:10 AM
edited to include versions and env
  • 1. Re: Control file multiplexed RAID question
    881508 Journeyer
    Currently Being Moderated
    Logically that would not be good approach. You will end up with multiple control file with variable read/write speed with different RAID. Suggested RAID for control file is 10 so its better to place them their.
  • 2. Re: Control file multiplexed RAID question
    861120 Explorer
    Currently Being Moderated
    Hi.

    Its not good ideia take place the controlfile in diferents RAIDs. It would be best if you put the same type of raid.

    The best recommended as RAID, as Nadeem said is RAID 10.
  • 3. Re: Control file multiplexed RAID question
    Victor Armbrust Oracle ACE
    Currently Being Moderated
    It's recommended to keep in same RAID config.

    Take a look
    http://www.google.com/translate?u=http%3A%2F%2Fvictor-dba.blogspot.com.br%2F2012%2F03%2Foracle-x-raid-melhores-praticas.html&langpair=pt%7cen&en=pt&en=utf8

    You can find a lot of information about RAID on MOS NOTE 30286.1


    Victor
  • 4. Re: Control file multiplexed RAID question
    Levi-Pereira Guru
    Currently Being Moderated
    Is there any cause for concern over design issues when placing multiplexed controlfiles on disks with different RAID types?
    IMHO, I believe not. Of course this depend on characteristic of I/O of each Array.
    As best practice never mix files stored on array with heavy I/O with array which has Low I/O.

    Controlfile is good for RAID 5 and RAID 10 no worry.

    Read note:

    I/O Tuning with Different RAID Configurations [ID 30286.1]
    Swap space can be used on RAID devices without affecting Oracle.   
             
    
    ====================================================================================
    RAID  Type of RAID        Control       Database        Redo Log        Archive Log
                                File          File            File            File
    ====================================================================================
    0     Striping             Avoid          OK           Avoid           Avoid     
    ------------------------------------------------------------------------------------
    1     Shadowing             OK             OK          Recommended       Recommended
    ------------------------------------------------------------------------------------
    0+1   Striping +            OK         Recommended       OK            Avoid     
          Shadowing                                                                                  
    ------------------------------------------------------------------------------------
    3     Striping with         OK           Avoid           Avoid            Avoid     
          Static Parity                                                                                         
    ------------------------------------------------------------------------------------
    5     Striping with         OK           Avoid           Avoid            Avoid     
          Rotating Parity                   
    ------------------------------------------------------------------------------------
    On this case the main concern is:
    Something which should help can disrupt and cause downtime.

    Unable To Open Database Due To Diskgroup Used To Multiplex The RedoLogs & Controlfiles & Archivelogs Got Corrupted. [ID 1382372.1]

    Regards,
    Levi Pereira

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