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Benefit of RAID 6 (6D+2P) over RAID-DP (6D+2P), in terms of performance point of view.

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  • 1.  Benefit of RAID 6 (6D+2P) over RAID-DP (6D+2P), in terms of performance point of view.

    Posted 23 days ago
    Hi All,

    Hope you are doing well.

    Can anyone let me know what is the benefit of RAID 6 (6D+2P) over RAID-DP (6D+2P), in terms of performance point of view?
     Why do we use RAID 6 (6D+2P) not RAID-DP(6D+2P) in the Hitachi Storage array?

    Thanks in advance.

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    Sumit Keshri
    Senior Test Engineer
    Hitachi Vantara
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  • 2.  RE: Benefit of RAID 6 (6D+2P) over RAID-DP (6D+2P), in terms of performance point of view.

    Posted 22 days ago
    Hi Sumit,

    To answer you query;

    1> RAID-DP is proprietary to NETAPP RAID implementation and hence there is no way we can use the same in Hitachi storage array.
    2> Hitachi Storage Array uses only the standard RAID implementation which includes RAID-6 as well but not RAID-DP.
    3> In case of RAID-6 we have dual parity which is distributed over all the drives but for RAID-DP we have dual DEDICATED parity. Now this has both advantages and disadvantages. Advantage of having RAID-DP over RAID-6 is growing the RAID set for RAID-DP is very easy as one has to just add new drives and the parity will be written in the dedicate drive only. Where as for RAID-6 it means redistributing stripes throughout all the drives along with the diagonal parity calculation. In terms of performance, RAID-DP is having dedicated parity disks and hence those can become bottleneck/hotspot where as with RAID-6 we have distributed parity and hence no such bottleneck issue.

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    Chayan Sarkar
    Hardware Test Engineer - Senior
    Hitachi Vantara
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