Date: Wed, 1 Jul 2020 15:59:58 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Nikhil Shetty <nikhil.dba04@gmail.com>
Cc: Haroldo Kerry <hkerry@callix.com.br>, Jeff Janes <jeff.janes@gmail.com>,
	Pgsql Performance <pgsql-performance@lists.postgresql.org>
Subject: Re: Recommended value for pg_test_fsync
Message-ID: <20200701195958.GA14460@momjian.us>
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On Wed, Jul  1, 2020 at 11:41:23PM +0530, Nikhil Shetty wrote:
> Hi,
> 
> The client has done benchmark tests on available storage using a storage
> benchmark tool and got IOPS of around 14k on iSCSI  and around 150k on HBA
> channel, which seems a good number but pg_test_fysnc gives numbers which are
> not reflecting good op/sec. Though pg_test_fysnc result should not be compared
> to benchmark throughput but both are indicative of overall database
> performance.

Well, by definition, pg_test_fsync asks for fsync after every set of
writes.  Only the last report, "Non-sync'ed 8kB writes:" gives non-fsync
performance.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee