Re: 8xIntel S3500 SSD in RAID10 on Dell H710p

On Wed, Dec 10, 2014 at 4:55 AM, Mark Kirkwood <
mark(dot)kirkwood(at)catalyst(dot)net(dot)nz> wrote:

> That is interesting: I've done some testing on this type of card with 16
> (slightly faster Hitachi) SSD attached. Setting WT and NORA should enable
> the so-called 'fastpath' mode for the card [1]. We saw performance improve
> markedly (300MB/s random write go to 1300MB/s).
>
> This *might* be related to the fact that 16 SSD can put out more IOPS than
> the card can actually handle - whereas your 8 S3500 is probably the perfect
> number (e.g 8*11000 = 88000 which the card can handle ok).
>
>
> [1] If you make the change while there are no outstanding background
> operations (array rebuild etc) in progress (see
> http://www.flagshiptech.com/eBay/Dell/poweredgeh310h710h810UsersGuide.pdf
> ).

I read that guide too, which is the reason why I tried with WT/NORA, but
the document also states: "NOTE: RAID 10, RAID 50, and RAID 60 virtual
disks cannot use FastPath." Which is a little odd, since usually if you
want performance with reliability, you go RAID10.

Do you have any suggestions what I could try to tweak to get more
performance?