Message-ID: <4E020F58.8090803@peak6.com>
Date: Wed, 22 Jun 2011 10:50:48 -0500
From: Shaun Thomas <sthomas@peak6.com>
Reply-To: <sthomas@peak6.com>
Organization: Peak6
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To: Greg Smith <greg@2ndQuadrant.com>
CC: Merlin Moncure <mmoncure@gmail.com>, Scott Marlowe
	<scott.marlowe@gmail.com>, Yeb Havinga <yebhavinga@gmail.com>,
	Florian Weimer <fweimer@bfk.de>, <pgsql-performance@postgresql.org>
Subject: Re: Contemplating SSD Hardware RAID
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On 06/21/2011 05:17 PM, Greg Smith wrote:

> If they just do the same style of write cache and reliability rework
> to the enterprise line, but using better flash, I agree that the
> first really serious yet affordable product for the database market
> may finally come out of that.

After we started our research in this area and finally settled on 
FusionIO PCI cards (which survived several controlled and uncontrolled 
failures completely intact), a consultant tried telling us he could 
build us a cage of SSDs for much cheaper, and with better performance.

Once I'd stopped laughing, I quickly shooed him away. One of the reasons 
the PCI cards do so well is that they operate in a directly 
memory-addressable manner, and always include capacitors. You lose some 
overhead due to the CPU running the driver, and you can't boot off of 
them, but they're leagues ahead in terms of safety.

But like you said, they're certainly not what most people would call 
affordable. 640GB for two orders of magnitude more than an equivalent 
hard drive would cost? Ouch. Most companies are familiar---and hence 
comfortable---with RAIDs of various flavors, so they see SSD performance 
numbers and think to themselves "What if that were in a RAID?" Right 
now, drives aren't quite there yet, or the ones that are cost more than 
most want to spend.

It's a shame, really. But I'm willing to wait it out for now.

-- 
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com

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