Re: optmize librbd for iops

[Stefan Priebe - Profihost AG <s.priebe@profihost.ag>]

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Am 13.11.2012 09:20, schrieb Josh Durgin:
> On 11/12/2012 11:55 PM, Stefan Priebe wrote:
> rados bench uses librados aio, keeping several operations in flight.
> IO size is the same as object size for it.
>
> You can do a 4k write benchmark that doesn't delete the objects it
> writes, with 32 IOs in flight for 300 seconds:
>
> rados -p data bench 300 write -b 4096 -t 32 --no-cleanup

This gives me just 9000 iop/s - callgraph attached.

> Then a read benchmark (only sequential is implemented, but with 4k
> objects it's similar to random if you flush the osd's page cache before
> running it):
>
> rados -p data bench 300 seq -b 4096 -t 32

This gives me 43 000 iops. But i'm sure readahead or a buffer is the 
burst here.

Greets,
Stefan

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