[Bizgres-general] Sizing a server to host Bizgres...

[Mark Kirkwood]

Charly Clairmont wrote:


> /dev/hda:
>  Timing buffered disk reads:   12 MB in  3.27 seconds =   3.67 MB/sec
> 

Oh dear! that's terrible IO performance! I'm guessing that you were 
doing the test while other read/write activity was happening?

Maybe try again after shutting the database (and anything else that is 
running) down and do 2 tests (1st one for writes, 2nd for reads):

$ time dd if=/dev/zero of=bigfile bs=8k count=524288
$ time dd if=bigfile of=/dev/null bs=8k


> I just want to know what is the smallest server (cpu, ram) I have to set
> up to test my bizgres data warehouse with 6,000,000 records a day ?
> 
>

It depends on how many days worth of data you wish to test (e.g. your 
current 1G of RAM is only ok for a few days worth of data). Your disk 
system is probably unsuitable for testing - as 1 ATA drive is not going 
to give you very representative IO behavior. Anything used in production 
would tend to be some sort of RAID setup - RAID1 (maybe ok for small 
data volumes) RAID5|6|10 (much better). Your cpu is probably fine, altho 
if you plan for high concurrency, then you need to think Opteron 
SMP/multicore.

A good way to proceed is to post to this list 1 or 2 of the queries that 
are slow (include the output from EXPLAIN ANALYZE of them, plus your 
postgresql.conf non-default settings)! Then lots of folks can chip in 
with tuning suggestions!

Once you have the queries running as well as they can on your current 
system, that will help to determine what new HW you might need to get in 
order to test for real.

Cheers

Mark