Re: Hardware recommendations

If you are IO-bound, you might want to consider using SSD.

A single SSD could easily give you more IOPS than 16 15k SAS in RAID 10.

--- On Wed, 12/8/10, Benjamin Krajmalnik <kraj@servoyant.com> wrote:

> From: Benjamin Krajmalnik <kraj@servoyant.com>
> Subject: [PERFORM] Hardware recommendations
> To: pgsql-performance@postgresql.org
> Date: Wednesday, December 8, 2010, 6:03 PM
> I need to build a new high
> performance server to replace our current production
> database server.
> The current server is a SuperMicro 1U with 2 RAID-1
> containers (one for data, one for log, SAS - data is 600GB,
> Logs 144GB), 16GB of RAM, running 2 quad core processors
> (E5405 @ 2GHz), Adaptec 5405 Controller with BBU.  I am
> already having serious I/O bottlenecks with iostat -x
> showing extended periods where the disk subsystem on the
> data partition (the one with all the random i/o) at over 85%
> busy.  The system is running FreeBSD 7.2 amd64 and
> PostgreSQL 8.4.4 on amd64-portbld-freebsd7.2, compiled by
> GCC cc (GCC) 4.2.1 20070719  [FreeBSD], 64-bit.
> Currently I have about 4GB of shared memory allocated to
> PostgreSQL.  Database is currently about 80GB, with about
> 60GB being in partitioned tables which get rotated nightly
> to purge old data (sort of like a circular buffer of
> historic data).
>
> I was looking at one of the machines which Aberdeen has
> (the X438), and was planning  on something along the lines
> of 96GB RAM with 16 SAS drives (15K).  If I create a RAID
> 10 (stripe of mirrors), leaving 2 hot spares, should I still
> place the logs in a separate RAID-1 mirror, or can they be
> left on the same RAID-10 container?
> On the processor front, are there advantages to going to X
> series processors as opposed to the E series (especially
> since I am I/O bound)?  Is anyone running this type of
> hardware, specially on FreeBSD?  Any opinions, especially
> concerning the Areca controllers which they use?
>
> The new box would ideally be built with the latest released
> version of FreeBSD, PG 9.x.  Also, is anyone running the
> 8.x series of FreeBSD with PG 9 in a high throughput
> production environment?  I will be upgrading one of our
> test servers in one week to this same configuration to test
> out, but just wanted to make sure there aren't any caveats
> others have experienced, especially as it pertains with the
> autovacuum not launching worker processes which I have
> experienced.
>
> Best regards,
>
> Benjamin
>
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