Re: Setting effective_io_concurrency in VM?

From: Andres Freund
Subject: Re: Setting effective_io_concurrency in VM?
Date: ,
Msg-id: 20171127235724.ec2ludkit57gdkoy@alap3.anarazel.de
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In response to: Re: Setting effective_io_concurrency in VM?  (Scott Marlowe)
List: pgsql-performance

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Setting effective_io_concurrency in VM?  (Don Seiler, )
 Re: Setting effective_io_concurrency in VM?  (Scott Marlowe, )
  Re: Setting effective_io_concurrency in VM?  (Jeff Janes, )
  Re: Setting effective_io_concurrency in VM?  (Andres Freund, )
  Re: Setting effective_io_concurrency in VM?  (Mark Kirkwood, )
 Re: Setting effective_io_concurrency in VM?  (Fernando Hevia, )
  Re: Setting effective_io_concurrency in VM?  (Andrew Kerber, )
   Re: Setting effective_io_concurrency in VM?  (Don Seiler, )

Hi,

On 2017-11-27 11:40:19 -0700, Scott Marlowe wrote:
> tl;dr: Only way to know is to benchmark it. I'd guess that somewhere
> between 10 and 20 is going to get the best throughput but that's just
> a guess. Benchmark it and let us know!

FWIW, for SSDs my previous experiments suggest that the sweet spot is
more likely to be an order of magnitude or two bigger. Depends a bit on
your workload (including size of scans and concurrency) obviously.

Greetings,

Andres Freund



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