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@xxxxxxx> wrote in message news:E8FEC853EDA289B924D8F213@xxxxxxxxxxxxxxxxxxxxxxxxx > 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@xxxxxxx > C&CT Sr. Systems Programmer Email, TeX, epistemology. > Rensselaer Polytechnic Institute, Troy, NY. http://www.rpi.edu/~sofkam/ > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend >
