From: Joshua D. Drake <jd@commandprompt.com>
To: Steve Crawford <scrawford@pinpointresearch.com>
To: Wes Vaske (wvaske) <wvaske@micron.com>
To: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: New server: SSD/RAID recommendations?
Date: Mon, 06 Jul 2015 10:20:29 -0700
Message-ID: <559AB8DD.5060708@commandprompt.com> (raw)
In-Reply-To: <559AB332.50304@pinpointresearch.com>
References: <CAFwQ8rfwyBMD7AiL659qtG+UhsOUZthLSBYF7ODTn6TKxJoTPg@mail.gmail.com>
<VisenaEmail.44.70ed435cef1739b1.14e4c07dd3d@tc7-visena>
<31701C89A44B714FB8D242F806E7286C5AED32FA@NTXBOIMBX01.micron.com>
<559AB332.50304@pinpointresearch.com>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>
On 07/06/2015 09:56 AM, Steve Crawford wrote:
> On 07/02/2015 07:01 AM, Wes Vaske (wvaske) wrote:
> For what it's worth, in my most recent iteration I decided to go with
> the Intel Enterprise NVMe drives and no RAID. My reasoning was thus:
>
> 1. Modern SSDs are so fast that even if you had an infinitely fast RAID
> card you would still be severely constrained by the limits of SAS/SATA.
> To get the full speed advantages you have to connect directly into the bus.
Correct. What we have done in the past is use smaller drives with RAID
10. This isn't for the performance but for the longevity of the drive.
We obviously could do this with Software RAID or Hardware RAID.
>
> 2. We don't typically have redundant electronic components in our
> servers. Sure, we have dual power supplies and dual NICs (though
> generally to handle external failures) and ECC-RAM but no hot-backup CPU
> or redundant RAM banks and...no backup RAID card. Intel Enterprise SSD
> already have power-fail protection so I don't need a RAID card to give
> me BBU. Given the MTBF of good enterprise SSD I'm left to wonder if
> placing a RAID card in front merely adds a new point of failure and
> scheduled-downtime-inducing hands-on maintenance (I'm looking at you,
> RAID backup battery).
That's an interesting question. It definitely adds yet another
component. I can't believe how often we need to "hotfix" a raid controller.
JD
--
Command Prompt, Inc. - http://www.commandprompt.com/ 503-667-4564
PostgreSQL Centered full stack support, consulting and development.
Announcing "I'm offended" is basically telling the world you can't
control your own emotions, so everyone else should do it for you.
--
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
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: jd@commandprompt.com, scrawford@pinpointresearch.com, wvaske@micron.com
Subject: Re: New server: SSD/RAID recommendations?
In-Reply-To: <559AB8DD.5060708@commandprompt.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