Hi Sébastien, On Thu, Aug 28, 2014 at 06:11:37PM +0200, Sebastien Han wrote: > Hey all, (...) > We have been able to reproduce this on 3 distinct platforms with some > deviations (because of the hardware) but the behaviour is the same. > Any thoughts will be highly appreciated, only getting 3,2k out of an 29K IOPS > SSD is a bit frustrating :).
Yes,
it's the OSD code running thru ~20k lines of code on every IO using ~1000
Systems-Calls for 1 real IO.
Please have a look at the attached page, which I presented last Sept at SDC.
=> Ceph (v0.61) used 1600 mys for a 4k IO, SSD ~60 mys, Network ~20-200 mys
(on v0.84 and all debug set to 0/0 it is still ~ 1100 mys)
=> so, tune or re-write the OSD code ... (I'm serious about this statement)
Mit freundlichen Grüßen / Best regards
Dieter
>
> Cheers.
> ????
> Sébastien Han
> Cloud Architect
>
> "Always give 100%. Unless you're giving blood."
>
> Phone: +33 (0)1 49 70 99 72
> Mail: [email protected]
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Ceph-OSD-TAT.pdf
Description: Adobe PDF document
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