From: Laurenz Albe <laurenz.albe@cybertec.at>
To: AB_ba# <bharti.anup@gmail.com>
To: pgsql-admin@lists.postgresql.org
Subject: Re: IO scheduler recommendation
Date: Mon, 21 Jan 2019 16:44:51 +0100
Message-ID: <df772cb764b99d4f4a454ee307840022c91bcdb6.camel@cybertec.at> (raw)
In-Reply-To: <CAHMim6rF6jxUp1ueJP593SwM4so7jsZC0vZaXOX2yD_z4XF9xQ@mail.gmail.com>
References: <CAHMim6rF6jxUp1ueJP593SwM4so7jsZC0vZaXOX2yD_z4XF9xQ@mail.gmail.com>
AB_ba# wrote:
> I searched the complete PostgreSQL Documentation but didn't get anything with respect to IO scheduler recommendation.
> What is being recommended by PostgreSQL ?
There is no clear recommendation.
I personally have seen workloads where changing from "cfq" to "deadline"
or "noop" improved performance by a factor of 4, but on many systems "cfq"
seems to be doing at least as good as the others.
I believe that it depends a lot on your hardware configuration and
your workload, and you are best advised to run a realistic load test.
> Which is the best IO scheduler considering the Data is hosted on NFS?
No idea - probably depends on what is behind the NFS.
Make sure to use hard, fg mounts.
If you can, use "jumbo frames" so that an 8KB block can fit into
a single IP frame.
Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com
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To: pgsql-admin@postgresql.org
Cc: laurenz.albe@cybertec.at, bharti.anup@gmail.com, pgsql-admin@lists.postgresql.org
Subject: Re: IO scheduler recommendation
In-Reply-To: <df772cb764b99d4f4a454ee307840022c91bcdb6.camel@cybertec.at>
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