[nycbug-talk] Memory sizing

[Pete Wright]

On Fri, Apr 21, 2006 at 11:47:56PM -0400, Francisco Reyes wrote:
> Soon to buy a couple of new server and wondering if we should get 4GB or 
> 8GB. My first stop is trying to better understand memory utilization.
> 
> Any suggested links?
> I have several machines simmilar machines to the functionality of one of the 
> new servers (mail machine), the second new server will be a PostgreSQL 
> database.. to host millions of records with about 250GB worth of data.
> 

the best i'd look for info on memory utilization in freebsd would be the
McKusick/Neville-Neil design and implementation book.  it's just a great
text in general, and should help you get a handle on how FreeBSD in
specific is going to utilize memory.

what is the profile on queries you are going to running against the
DB?  are we looking at lot's of small queries, periodic quries on large
data set's or something in between.  i am in the process of building a
large postgres server that is going to be doing data warehousing, we are
thinking that we should be fine with 4gig's or RAM as we will not have
many concurrent connections.

if you are going to have many people hitting this thing, then yea i'd
give it as much memory as practical and the fastest storage i can
afford.

as an aside, i have another postgres DB that we are running out of a
memory FS.  it's execellent, although took a bit of work on our end to
architect a solution that would work this way.  the database in the memfs
partition does not persist between reboot's - it populates itself off
an oracle server (and through some other methods) between reboots.  it
has been very successfull performance wise, although granted such a
solution may not fit everyone's environment.


HTH
-p


-- 
~~oO00Oo~~
Peter Wright
pete at nomadlogic.org
www.nomadlogic.org/~pete
310.869.9459