pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Nicolas Charles <nicolas.charles@normation.com>
To: Robert Zenz <robert.zenz@sibvisions.com>
To: pgsql-performance@lists.postgresql.org <pgsql-performance@lists.postgresql.org>
Subject: Re: Why HDD performance is better than SSD in this case
Date: Tue, 17 Jul 2018 16:08:28 +0200
Message-ID: <24d62ee0-edd6-fd53-3a3d-8ab1dacd9c35@normation.com> (raw)
In-Reply-To: <5B4DF40E.7080803@sibvisions.com>
References: <CA+wPC0PsWacZpNX2OfRSSauUg9iNa7tReJU0oTLnM7K8PFFt6A@mail.gmail.com>
	<01bbbc88-2a47-f078-ea40-ab2c1acafa1f@portavita.eu>
	<CA+wPC0M=e5ZXd1NF1nz6mYfmPgys89vB4A74GmxnnK+KpA4_XA@mail.gmail.com>
	<CA+wPC0MVVpJqHf5D79Od1mMGAeATEiZWaEwoFRr5q6n_EO+F1w@mail.gmail.com>
	<bc55990f-e1ac-10c1-8a6d-2d4aef9e9ab7@normation.com>
	<5B4DF40E.7080803@sibvisions.com>

Le 17/07/2018 à 15:50, Robert Zenz a écrit :
> On 17.07.2018 15:44, Nicolas Charles wrote:
>> - Partitions is not correctly aligned on the SSD blocks
> Does that really make a noticeable difference? If yes, have you got some further
> reading material on that?

I was pretty sure it was, but looking at the litterature, it's not that 
obvious. Especially 
https://blog.pgaddict.com/posts/postgresql-performance-on-ext4-and-xfs 
seems to mentions that it doesn't change a thing, while others stress 
out that it is mandatory ( https://www.alibabacloud.com/forum/read-415, 
https://www.thomas-krenn.com/en/wiki/Partition_Alignment )
Even on mecanical drives it's been reported to cause slowdown ( 
https://www.ibm.com/developerworks/library/l-linux-on-4kb-sector-disks/index.html 
)

Maybe the OS are more clever now, making it not so important as before ?

Nicolas




view thread (32+ messages)  latest in thread

Message-ID: <24d62ee0-edd6-fd53-3a3d-8ab1dacd9c35@normation.com>
Permalink:  ../24d62ee0-edd6-fd53-3a3d-8ab1dacd9c35@normation.com/
Also on:    postgresql.org/message-id/24d62ee0-edd6-fd53-3a3d-8ab1dacd9c35@normation.com

 · 

reply
Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-performance@postgresql.org
  Cc: nicolas.charles@normation.com, robert.zenz@sibvisions.com, pgsql-performance@lists.postgresql.org
  Subject: Re: Why HDD performance is better than SSD in this case
  In-Reply-To: <24d62ee0-edd6-fd53-3a3d-8ab1dacd9c35@normation.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox