Message-ID: <4ECD0EE8.5030401@2ndQuadrant.com>
Date: Wed, 23 Nov 2011 10:19:04 -0500
From: Greg Smith <greg@2ndQuadrant.com>
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To: pgsql-performance@postgresql.org
Subject: Re: SSD endurance calculations
References: <zarafa.4ecabcb2.0527.762392872b021f28@meel.technocon.local>
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On 11/21/2011 04:03 PM, Christiaan Willemsen wrote:
>
> Secondly, I also looked at the reliability figures of the Intel 320. 
> They show 5 years of 20GB per day, meaning that it will hold up for 
> about 200 days in our system. RAID 10 wil make 400 days of that, but 
> this seems hardly a lot.. Am I missing something here?
>

The 320 series drives are not intended for things that write as heavily 
as you do.  If your database is growing fast enough that you're going to 
hit a terabyte in a short period of time, just cross that right off the 
list of possibilities.  Intel's 710 series is the one aimed at your sort 
of workload.

You can probably pull down the total write volume on your system by more 
aggressively running VACUUM FREEZE shortly after new data is loaded.  
PostgreSQL tends to write blocks even in INSERT-only tables several 
times; forcing them to freeze early can eliminate several of them.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us