From: Greg Smith <greg@2ndQuadrant.com>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Tomas Vondra <tv@fuzzy.cz>
Cc: pgsql-performance@postgresql.org
Subject: Re: Reliability with RAID 10 SSD and Streaming Replication
Date: Tue, 21 May 2013 20:19:09 -0400
Message-ID: <519C0EFD.9080002@2ndQuadrant.com> (raw)
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On 5/20/13 6:32 PM, Merlin Moncure wrote:
> When it comes to databases, particularly in the open source postgres
> world, hard drives are completely obsolete. SSD are a couple of
> orders of magnitude faster and this (while still slow in computer
> terms) is fast enough to put storage into the modern area by anyone
> who is smart enough to connect a sata cable.
You're skirting the edge of vendor Kool-Aid here. I'm working on a very
detailed benchmark vs. real world piece centered on Intel's 710 models,
one of the few reliable drives on the market. (Yes, I have a DC S3700
too, just not as much data yet) While in theory these drives will hit
two orders of magnitude speed improvement, and I have benchmarks where
that's the case, in practice I've seen them deliver less than 5X better
too. You get one guess which I'd consider more likely to happen on a
difficult database server workload.
The only really huge gain to be had using SSD is commit rate at a low
client count. There you can easily do 5,000/second instead of a
spinning disk that is closer to 100, for less than what the
battery-backed RAID card along costs to speed up mechanical drives. My
test server's 100GB DC S3700 was $250. That's still not two orders of
magnitude faster though.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
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To: pgsql-performance@postgresql.org
Cc: greg@2ndQuadrant.com, mmoncure@gmail.com, tv@fuzzy.cz
Subject: Re: Reliability with RAID 10 SSD and Streaming Replication
In-Reply-To: <519C0EFD.9080002@2ndQuadrant.com>
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