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Comment by joevandyk | Hacker News Reader

Did you use Raid10? I would love to see a post on using postgresql with ec2/ebs -- how to setup raid, etc.

Orion Henry at Heroku wrote about this and described different software RAID configurations and the performance characteristics of each a while back:

http://orion.heroku.com/past/2009/7/29/io_performance_on_ebs...

Yes, but as a lowly developer, I have no idea how to set read-ahead buffers or change io schedulers.

Plus, that's a year old, would love to see some updated advice. You'd think Amazon would write more guides like this.

Well, that's really just "-setra" and other file system mounting options, and mdadm (Linux software RAID) configuration options. Yes, there's a little bit of a learning curve and pain to get things set up, but it's not completely out of reach.

Despite being relatively old, I think the advice and approach still holds. Clearly, EBS hasn't improved since then and the need to do this kind of striping over EBS volumes hasn't been obviated yet.

I found a benchmark from 2008 that details the problems with RAID10 and sourced it in a comment above [1]. These are just raw disk transfer numbers, though. I can only imagine how they would change as CPU usage/postgres load climbs. IIRC disk IO is network traffic and network traffic is CPU dependent, so as load increases, IO will suffer greatly.

[1] http://news.ycombinator.com/item?id=2341425

Build-out Script for Postgres/PostGIS with RAID 10 on Amazon EBS volumes: http://sproke.blogspot.com/2010/12/build-out-script-for-post...

I second that.

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