From: Bruce Momjian <bruce@momjian.us>
To: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
Cc: Gregg Jaskiewicz <gryzman@gmail.com>
Cc: Greg Smith <greg@2ndquadrant.com>
Cc: postgres performance list <pgsql-performance@postgresql.org>
Cc: Niels Kristian Schjødt <nielskristian@autouncle.com>
Subject: Re: New server setup
Date: Thu, 14 Mar 2013 18:34:49 -0400
Message-ID: <20130314223449.GE28770@momjian.us> (raw)
In-Reply-To: <51424333.608@catalyst.net.nz>
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On Fri, Mar 15, 2013 at 10:37:55AM +1300, Mark Kirkwood wrote:
> On 15/03/13 07:54, Bruce Momjian wrote:
> >Only use SSDs with a BBU cache, and don't set SSD caches to
> >write-through because an SSD needs to cache the write to avoid wearing
> >out the chips early, see:
> >
> > http://momjian.us/main/blogs/pgblog/2012.html#August_3_2012
> >
>
> I not convinced about the need for BBU with SSD - you *can* use them
> without one, just need to make sure about suitable longevity and
> also the presence of (proven) power off protection (as discussed
> previously). It is worth noting that using unproven or SSD known to
> be lacking power off protection with a BBU will *not* save you from
> massive corruption (or device failure) upon unexpected power loss.
I don't think any drive that corrupts on power-off is suitable for a
database, but for non-db uses, sure, I guess they are OK, though you
have to be pretty money-constrainted to like that tradeoff.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
--
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Cc: bruce@momjian.us, mark.kirkwood@catalyst.net.nz, gryzman@gmail.com, greg@2ndquadrant.com, nielskristian@autouncle.com
Subject: Re: New server setup
In-Reply-To: <20130314223449.GE28770@momjian.us>
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