Re: higher read iop/s for single thread

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I'm not sure you will be able to get there with firefly. I've gotten close to 1ms after lots of tuning on hammer, but 0.5ms is probably not likely to happen without all of the new work that Sandisk/Fujitsu/Intel/Others have been doing to improve the data path.

Your best bet is probably going to be a combination of:

1) switch to jemalloc (and make sure you have enough RAM to deal with it)
2) disabled ceph auth
3) disable all logging
4) throw a high clock speed CPU at the OSDs and keep the number of OSDs per server lowish (will need to be tested to see where the sweet spot is). 5) potentially implement some kind of scheme to make sure OSD threads stay pinned to specific cores. 6) lots of investigation to make sure the kernel/tcp stack/vm/etc isn't getting in the way.

Mark

On 09/10/2015 08:34 AM, Stefan Priebe - Profihost AG wrote:
Hi,

while we're happy running ceph firefly in production and also reach
enough 4k read iop/s for multithreaded apps (around 23 000) with qemu 2.2.1.

We've now a customer having a single threaded application needing around
2000 iop/s but we don't go above 600 iop/s in this case.

Any tuning hints for this case?

Stefan
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