Re: Server Hardware Configuration - Mailing list pgsql-admin

Way overkill... all you really need is a decently sized (160G or a pair of
80's) hard-disk and a P-III / AMD Athlon 750 MHz with 512MB Ram and FreeBSD
5 and postgreSQL....

With databases... it's all about disk-performance anyway...



""Michael D. Sofka"" <sofkam@rpi.edu> wrote in message
news:E8FEC853EDA289B924D8F213@betelgeuse.cct.rpi.edu...
> We are running PostgreSQL as the back-end to a spam scanning system.  The
> database holds suspected spam, and user configuration information.  A
> web interface allows people to accept, or (usually) discard the trapped
> messages.   So, most data is write once, read at most once, delete.
>
> The total size of the db is about 16gig in size.  And, we expect it
> could grow to 4 times this as more users are opted into spam scanning.
> During most of the day, the machine is only lightly loaded.  There are
> two bursts of activity: the nightly vacuum, and the first thing in the
> morning spam checking.
>
> Our current db machine has two hyper-threaded 2.4 GHz Xeon processors, 4
> gig of main memory, and is attached to a JBOD configured with RAID 5 for
> the database, and mirrored disks for the DB logs.
>
> It is time to upgrade the machine.   Two possibilities present themselves.
>
>    1.  PowerEdge 6850
>        4 3.16 GHz Xeon processors
>        16 gig of memory
>        Internal RAID 5 (only 3 disks)
>        2 Mirrored disks for root and db log.
>
>    2.  PowerEdge 2850
>        2 Dual core 2.8GHz Xeon processors
>        8 gig of memory
>        JBOD with RAID 5, and mirrored db log.
>
> Both configurations will cost about the same, within $\Delta$ for an
> acceptable value of $\Delta$.  The idea behind the first is to keep the
> entire database in memory, by way of the disk cache.  Alas, to keep it
> affordable (The extra memory is expensive) the JBOD must be jettisoned.
> The second is a larger version of our current configuration.  (The 6850
> with a JBOD would stretch the budget beyond $\Delta$, and the expense
> would be difficult to justify.)
>
> I'm looking for any comments, or suggestions.  With expected growth, the
> first configuration seems out of balance---it will likely start off
> fast, but with growth the slower disk configuration will likely be a
> problem.  Is anybody running PostgreSQL in a large memory, slower disk
> configuration?  What are your experiences.
>
> Thank You,
>
> Mike
>
> P.S. We are investigating if the current IBM JBOD will work with the
> Dell PERC cards.  But, even if they do, the current JBOD is populated
> with soon to be extended warranty disks, and so progressively costly.
>
> --
> Michael D. Sofka              sofkam@rpi.edu
> C&CT Sr. Systems Programmer    Email, TeX, epistemology.
> Rensselaer Polytechnic Institute, Troy, NY.  http://www.rpi.edu/~sofkam/
>
>
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