From: Joshua D. Drake <jd@commandprompt.com>
To: David F. Skoll <dfs@roaringpenguin.com>
Cc: pgsql-admin@postgresql.org
Subject: Re: Opinions on SSDs
Date: Mon, 12 Aug 2013 08:33:04 -0700
Message-ID: <52090030.4000503@commandprompt.com> (raw)
In-Reply-To: <20130812112833.65a97285@hydrogen.roaringpenguin.com>
References: <20130812112833.65a97285@hydrogen.roaringpenguin.com>
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On 08/12/2013 08:28 AM, David F. Skoll wrote:
>
> Hi,
>
> We run a fairly write-intensive workload and are looking at upgrading
> our Pg servers. (PostgreSQL 9.1; no practical way to upgrade to 9.2 for
> a while because we use what's packaged with Debian.)
apt.postgresql.org
>
> I'm considering the following configuration:
>
> Dual 4-core Intel CPU (E5620 at 2.4GHz)
>
> 192GB of RAM
>
> Sixteen 240GB Intel SSD 520 series drives arranged using Linux
> RAID-10. The RAID 10 array will use eight mirrored stripes using the
> "offset-copies" RAID10 scheme.
>
> Questions:
>
> 1) Has anyone had experience with Intel 520 SSDs? Are they reliable?
> When they fail, do they fail nicely (ie, failure detected and bad drive
> removed from RAID array) or horribly (data silently corrupted...) ?
I don't recall if the 520s have powerloss protection but you will want
to check that.
>
> 2) Is this RAID arrangement sensible? I've seen reports where some
> people keep the pg_xlog directory on a separate RAID array, but I
> don't really see the advantage with SSDs.
Put the pg_xlog on spindles, they are more than fast enough and won't
eat up the write life of your SSDs.
JD
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To: pgsql-admin@postgresql.org
Cc: jd@commandprompt.com, dfs@roaringpenguin.com
Subject: Re: Opinions on SSDs
In-Reply-To: <52090030.4000503@commandprompt.com>
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