Message-ID: <46BB6F3D.6090608@gmail.com>
Date: Thu, 09 Aug 2007 15:47:09 -0400
From: Joe Uhl <joeuhl@gmail.com>
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To: pgsql-performance@postgresql.org
Subject: Dell Hardware Recommendations
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We have a 30 GB database (according to pg_database_size) running nicely
on a single Dell PowerEdge 2850 right now.  This represents data
specific to 1 US state.  We are in the process of planning a deployment
that will service all 50 US states.

If 30 GB is an accurate number per state that means the database size is
about to explode to 1.5 TB.  About 1 TB of this amount would be OLAP
data that is heavy-read but only updated or inserted in batch.  It is
also largely isolated to a single table partitioned on state.  This
portion of the data will grow very slowly after the initial loading. 

The remaining 500 GB has frequent individual writes performed against
it.  500 GB is a high estimate and it will probably start out closer to
100 GB and grow steadily up to and past 500 GB.

I am trying to figure out an appropriate hardware configuration for such
a database.  Currently I am considering the following:

PowerEdge 1950 paired with a PowerVault MD1000
2 x Quad Core Xeon E5310
16 GB 667MHz RAM (4 x 4GB leaving room to expand if we need to)
PERC 5/E Raid Adapter
2 x 146 GB SAS in Raid 1 for OS + logs.
A bunch of disks in the MD1000 configured in Raid 10 for Postgres data.

The MD1000 holds 15 disks, so 14 disks + a hot spare is the max.  With
12 250GB SATA drives to cover the 1.5TB we would be able add another
250GB of usable space for future growth before needing to get a bigger
set of disks.  500GB drives would leave alot more room and could allow
us to run the MD1000 in split mode and use its remaining disks for other
purposes in the mean time.  I would greatly appreciate any feedback with
respect to drive count vs. drive size and SATA vs. SCSI/SAS.  The price
difference makes SATA awfully appealing.

We plan to involve outside help in getting this database tuned and
configured, but want to get some hardware ballparks in order to get
quotes and potentially request a trial unit.

Any thoughts or recommendations?  We are running openSUSE 10.2 with
kernel 2.6.18.2-34.

Regards,

Joe Uhl
joeuhl@gmail.com